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Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act:

Indicate the number of outstanding shares of each of the Issuer’sissuer’s classes of capital or common stock as of the close of the period covered by the annual report: 51,167,22867,600,654 ordinary shares, par value $0.01 per ordinary share.share, as of December 31, 2017.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

x Yes   o No

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

o Yes   x No

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

x Yes   o No

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

x Yes   o No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer.filer, or an emerging growth company. See definitionthe definitions of “large accelerated filer,” “accelerated filer,” and large accelerated filer”“emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one):

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to Section 13(a) of the Exchange Act. o

†The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.

o Item 17   o Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

o Yes   x No

(APPLICABLE ONLY TO ISSUERS INVOLVED IN BANKRUPTCY PROCEEDINGS DURING THE PAST FIVE YEARS.)

Indicate by check mark whether the registrant has filed all documents and reports required to be filed by Sections 12, 13 or 15(d) of the Securities Exchange Act of 1934 subsequent to the distribution of securities under a plan confirmed by a court.

o Yes   o No

Table of Contents

TABLE OF CONTENTS

INTRODUCTION

In this annual report, unless otherwise indicated or unless the context otherwise requires:

(1)·                        “ADSs” refers to our American depositary shares, each of which represents 0.125 ordinary share;

·                        “China” or “PRC” refers to the termsPeople’s Republic of China and, solely for the purpose of this annual report, excludes Taiwan, Hong Kong, and Macau, and “Greater China” refers to the People’s Republic of China, Taiwan, Hong Kong, and Macau;

·                        “Qunar” refers to Qunar Cayman Islands Limited, a Cayman Islands company, and unless the context requires otherwise, includes its predecessor entities and consolidated subsidiaries and variable interest entities;

·                        “RMB” or “Renminbi” refers to the legal currency of China; “U.S. dollars,” “dollars,” “US$,” or “$” refers to the legal currency of the United States; “£” refers to the legal currency of the United Kingdom; “€” refers to the legal currency of Eurozone;

·                        “shares” or “ordinary shares” refers to our ordinary shares, par value of US$0.01 per share; and

·                        “we,” “us,” “our company,” “our” andor “Ctrip” referrefers to Ctrip.com International, Ltd., its predecessor entities and subsidiaries and, in the context of describing our operations and consolidated financial information, also include its consolidated affiliated Chinese entities;

(2) “shares”entities, unless otherwise indicated herein. We consolidate the financial results of Qunar starting from December 31, 2015. In calculating the number of hotels with which we have room supply relationships, downloads of and “ordinary shares” refer totransactions through our ordinary shares, par valuemobile channel, outbound travel business, and other operational data, where applicable, as well as in describing our marketing, branding, and intellectual properties, we have not taken into account the comparable operating data or other information of US$0.01 per ordinary share;

(3) “ADSs” refers to our American depositary shares, eight of which represent one ordinary share, unless the context suggests otherwise;

(4) “China” and “PRC” refer to the People’s Republic of China and, solely for the purpose of this annual report, exclude Taiwan, Hong Kong and Macau, and “Greater China” refers to the PRC, Taiwan, Hong Kong and Macau; and

(5) all references to “RMB” and “Renminbi” are to the legal currency of China and all references to “U.S. dollars,” “US$,” “dollars” and “$” are to the legal currency of the United States.Qunar.

Any discrepancies in any table between the amounts identified as total amounts and the sum of the amounts listed therein are due to rounding.

This annual report on Form 20-F includes our audited consolidated financial statements for the years ended December 31, 2013, 20142015, 2016, and 2015.2017.

On January 21, 2010,December 1, 2015, we effected a change of the ratio of ourthe ADSs to ordinary shares from two (2)four ADSs representing one ordinary share to four (4) ADSs representing one ordinary share. Effective December 1, 2015, we further changed our ADS to ordinary share ratio from four (4) ADSs representing one ordinary share to eight (8) ADSs representing one ordinary share. Unless otherwise indicated, ADSs and per ADS amount in this annual report have been retroactively adjusted to reflect the changes in ratio for all periods presented.

PART II.

ITEM 1.        IDENTITY OF DIRECTORS, SENIOR MANAGEMENT AND ADVISERS

Not applicable.

ITEM 2.        OFFER STATISTICS AND EXPECTED TIMETABLE

Not applicable.

ITEM 3.        KEY INFORMATION

A.Selected Financial Data

Selected Consolidated Financial Data

The following table presents the selected consolidated financial information for our business. You should read the following information in conjunction with “Item 5. Operating and Financial Review and Prospects” below. The selected consolidated statement of operations data for the years ended December 31, 2013, 20142015, 2016, and 20152017 and the selected consolidated balance sheet data as of December 31, 20142016 and 20152017 have been derived from our audited consolidated financial statements and should be read in conjunction with those statements, which are included in this annual report beginning on page F-1. The selected consolidated statement of operations data for the years ended December 31, 20112013 and 20122014 and the selected consolidated balance sheet data as of December 31, 2011, 20122013, 2014, and 20132015 have been derived from our audited consolidated financial statements for these periods, which are not included in this annual report.

All ADS data have been retroactively adjusted to reflect the current ADS to ordinary share ratioOur historical results do not necessarily indicate results expected for all periods presented.any future periods.

(1)         Our consolidated balance sheet data has reflected the effect of consolidation of Qunar’s financial statements starting from December 31, 2015. Our consolidated statement of operation data has reflected the effect of consolidation of Qunar’s financial statements starting from January 1, 2016.

(2)         Translation from Renminbi amounts into U.S. dollar amounts was made at a rate of RMB6.5063 to US$1.00. See “Item 3.A. Key Information—Selected Financial Data—Exchange Rate Information.”

(3)         Share-based compensation was included in the related operating expense categories as follows:

(2)   Translation from RMB amounts into U.S. dollars(4)         In 2015, a gain of RMB2.3 billion was made atrecognized in the other income for the deconsolidation of Tujia, which was once a ratesubsidiary of RMB6.4778 to US$1.00. See “Item 3. Key Information — A. Selected Financial Information — Exchange Rate Information.”our company.

(3)(5)         Each ADS represents 0.125 of an ordinary share.

(6)         In 2015, we determined and elected to early adopt ASU 2015-17 to our consolidated financial statements starting December 31, 2015, prospectively to present the deferred tax assets and liabilities as non-current items.

(4)(7)         In April 2015, the FASB issued new guidance which changes the presentation of debt issuance cost. Under the new guidance, debt issuance cost is presented as a reduction of the carrying amount of the related liability, rather than as an asset. This guidance has been adopted and applied retrospectively by us to the prior periods presented herein.

(5)   In 2015, a gain of RMB2.3 billion (US$350 million) was recognized in the other income for the deconsolidation of Tujia which was once a subsidiary of the Company. Please refer to footnote 8 of our consolidated financial statements incorporated herein.

(6)   In 2015, we have determined and elected to early adopt ASU 2015-17 to our consolidated financial statements starting December 31, 2015, prospectively to present the deferred tax assets and liabilities as non-current items.

(7)   Our consolidated balance sheet data has reflected the effect of consolidation of the financial statements of Qunar Cayman Islands Limited starting from December 31, 2015.

Exchange Rate Information

We have published our consolidated financial statements in RMB.Renminbi. Our business is primarily conducted in China using RMB.in Renminbi. The conversion of RMBRenminbi into U.S. dollars in this annual report is based on the certified exchange rate published by the Federal Reserve Board. For your convenience, this annual report contains translations of some RMBRenminbi or U.S. dollar amounts for 20152017 at a rate of RMB6.4778RMB6.5063 to US$1.00, which was the certified exchange rate in effect as of December 31, 2015.29, 2017. The certified exchange rate on April 15, 201613, 2018 was RMB6.4730RMB6.2725 to US$1.00. We make no representation that any RMBRenminbi or U.S. dollar amounts could have been, or could be, converted into U.S. dollars or RMB,Renminbi, as the case may be, at any particular rate, the rates stated below, or at all. The PRC government imposes control over its foreign currency reserves in part through direct regulation of the conversion of RMBRenminbi into foreign exchange.

The following table sets forth information concerning exchange rates between the RMBRenminbi and the U.S. dollars for the periods indicated. The exchange rates refer to the exchange rates as set forth in the H.10 statistical release of the Federal Reserve Board. These rates are provided solely for your convenience and are not necessarily the exchange rates that we used in this annual report or will use in the preparation of our periodic reports or any other information to be provided to you. The source of these rates is the Federal Reserve Statistical Release.

(1)         Annual averages are calculated using the average of month-end rates of the relevant year. Monthly averages are calculated using the average of the daily rates during the relevant period.month.

B.Capitalization and Indebtedness

Not applicable.

C.Reasons for the Offer and Use of Proceeds

Not applicable.

D.Risk Factors

Risks Related to Our Company

Our business could suffer if we do not successfully manage current growth and potential future growth.

Our business has grown significantly as a result of both organic growth of existing operations and acquisitions, and we expect to continue to experience such growth in the future. We have significantly expanded our operations and anticipate further expansion of our operations and workforce, as a result of the continued growth of our service offerings, customer base and geographic coverage. For example, we have invested in, and plan to continue to invest in, organic growth by rolling out new business initiatives focusing in a diverse range of areas including cruise lines, car services, bus tickets and train tickets. Consequentially, in 2017, we invested US$1.3 billion in product development. If such new business initiatives fail to perform as expected, our financial condition and results of operations could be adversely affected. Our growth to date has placed, and our anticipated future operations will continue to place, a significant strain on our management, systems and resources. In addition to training and managing our workforce, we will need to continue to improve and develop our financial and managerial controls and our reporting systems and procedures. We cannot assure you that we will be able to efficiently or effectively manage the growth of our operations, and any failure to do so may limit our future growth and hamper our business strategy.

Strategic acquisition of complementary businesses and assets, and the subsequent integration of newly acquired business into our own, create significant challenges that may have a material adverse effect on our business, reputation, results of operations and financial condition.

We have made and intend to continue to make strategic acquisitions in the travel industry in Greater China and overseas. For example, in October 2015, we completed a share exchange transaction with Baidu Inc., or Baidu, whereby we obtained approximately 45% of the aggregate voting interest of Qunar in exchange for our newly issued ordinary shares. Subsequently, we issued ordinary shares represented by ADSs to certain special purpose vehicles holding shares solely for the benefit of certain Qunar employees and, in return, we received Class B ordinary shares of Qunar from these employees. We directly injected these shares to a third-party investment entity dedicated to investing in business in China. From an accounting perspective, we consolidated the financial statements of these non-U.S. investment entities and started to consolidate Qunar’s financial statements from December 31, 2015. In October 2016, we participated as a member in the buying consortium in Qunar’s going-private transaction and rolled our then existing equity stake into the entity that wholly owns Qunar upon the completion of the transaction in February 2017.

If we are presented with appropriate opportunities, we may continue to acquire complementary businesses and assets in the future. However, strategic acquisitions and the subsequent integration of new businesses and assets into our own would require significant attention from our management and could result in a diversion of resources from our existing business, which in turn could have an adverse effect on our business operations. In addition, acquisitions could result in potential dilutive issuances of equity securities, use of substantial amounts of cash, and exposure to potential ongoing financial obligations and unforeseen or hidden liabilities of the acquired business. The cost and duration of, and difficulties in, integrating newly acquired businesses and managing a larger overall business could also materially exceed our expectations. Moreover, we may not be able to achieve our intended strategic strategies and record substantial impairment charges to goodwill, if we fail to successfully integrate the newly acquired business or manage a larger business. Any such negative developments could have a material adverse effect on our business, reputation, results of operations and financial condition.

Our strategy to acquire or invest in complementary businesses and assets and establish strategic alliances involves significant risk and uncertaintyuncertainties that may prevent us from achievinghave a material adverse effect on our objectives and harm our financial condition andbusiness, reputation, results of operations.operations and financial condition.

As part of our plan to expand our product and service offerings, we have made and intend to make strategic acquisitions or investments in the travel service industries in Greater China and overseas. For example,overseas, such as the following, in addition to our transactions relating to Qunar described elsewhere in this annual report:

·                  In May 2015, we hadacquired approximately 38% share capital of eLong, Inc. In May 2016, eLong, Inc. completed its going-private transaction and merger with E-dragon Holdings Limited, or eLong. In December 2017, eLong and Tongcheng Network Technology Co., Ltd., or LY.com, announced an agreement to merge and form Tongcheng-Elong Holdings Limited, which was consummated in March 2018. In exchange for our prior holdings in eLong, we received an equity method investment in the enlarged group.

·                  In January 2016, we invested through openUS$180 million in MakeMyTrip Limited, or MakeMyTrip, India’s largest online travel company, via convertible notes, and subsequently appointed a director to MakeMyTrip’s board of directors. In October 2016, we converted all of the outstanding principal amount of convertible notes into ordinary shares of MakeMyTrip. In May 2017, we further invested approximately US$33 million in MakeMyTrip by subscribing for 916,666 of its ordinary shares. As of December 31, 2017, based on the market purchasesprice, we re-measured the investment at a fair value of approximately RMB2.1 billion.

·                  In April 2016, we announced strategic collaboration with China Eastern Airlines Corporation Limited, or China Eastern Airlines, one of China’s three major air transportation groups, on a broad range of products and services. In June 2016, we invested approximately RMB3.0 billion in approximately 466 million A shares of China Eastern Airlines in a private placementplacement.

·                  In December 2016, we consummated an acquisition transaction whereby shares held by nearly all the shareholders of Skyscanner Holdings Limited, or Skyscanner, a totalleading global travel search site headquartered in Edinburgh, the United Kingdom, were acquired by Ctrip.

·                  In December 2016, in connection with our share exchange transaction with BTG Hotels (Group) Co., Ltd., or BTG, a PRC joint stock company that is listed on the Shanghai Stock Exchange and principally engaged in the management of US$92 million in an approximately 15% stake inhotels and tourism destinations, and Homeinns Hotel Group, or Homeinns, a leading economy hotel chainwe exchanged our previously held equity interest in China. In June 2015, we, together with our co-founder and chief executive officer Mr. James Jianzhang Liang, our co-founder and independent director Mr. Neil Nanpeng Shen and certain other buyers, delivered a non-binding letter to Homeinns which proposes to acquire all of its outstanding ordinary shares not already owned by these buyers for a cash consideration of US$35.8 per ADS; in December 2015, an agreement and plan of merger was entered into between Homeinns and the special purpose vehicles formed by our consortium to consummate the transaction. In March 2010, we invested a total of US$67.5 million in approximately 9% stake in China Lodging Group, Limited, or Hanting, a leading economy hotel chain in China, through private placement transactions and purchases in Hanting’s initial public offering. As a result of a series of investments on eHi since 2013, we held an aggregate22% equity interest of approximately 14% in eHi as of December 31, 2015 with the aggregated investment cost of US$107 million. In 2014 and 2015, we invested a total of US$50 million in approximately 4% stake in Tuniu Corporation, or Tuniu, a well-known service provider in the leisure package tour market, through a private placement transaction conducted concurrently with Tuniu’s initial public offering and private acquisitions afterwards. In May 2015, we made an investment in eLong, Inc., or eLong, through acquiring the shares of eLong from certain selling shareholders, including Expedia, Inc., or Expedia, together with several other investors. We acquired a 38% equity stake in eLong for a total purchase price of US$422 million. In October 2015, we completed a share exchange transaction with Baidu, Inc., or Baidu, and obtained approximately 45% of the aggregate voting interest of Qunar Cayman Islands Limited, or Qunar, in exchange for our newly issued ordinary shares. In December 2015, we issued ordinary shares represented by ADSs to certain special purpose vehicles holding shares solely for the benefit of certain Qunar employees and, as consideration, we received class B ordinary shares of Qunar and directly injected these shares to third-party investment entities dedicated to investing in business in China. From accounting perspective, we started to consolidate Qunar’s financial statements from December 31, 2015. BTG.

If the ADS or share prices of Hanting, eHi,the public companies that we have invested in or may invest in the future which are classified as available-for-sale investments decline and Tuniu, or other future public company targets declines and becomesbecome lower than our share purchase price,prices, as have happened historically, we could incur impairment loss under U.S. GAAP, which in turn would adversely affect our financial results for the relevant periods. In addition, if any of Homeinns and eLongour investees in which our investments are classified as equity method investments incur a net losslosses in the future, we wouldwill share their net losslosses proportionate to our equity interest in them.

In connection with our recentOur strategic acquisitions, there had been a significant increase of goodwill and indefinite lived intangible assets booked in our financial statements. As of December 31, 2015, our goodwill was RMB45.7 billion (US$7.1 billion) and our indefinite lived intangible assets were RMB9.7 billion (US$1.5 billion). ASC 350 “Intangibles — Goodwill and Other,” provides that intangible assets that have indefinite useful lives and goodwill will not be amortized but rather will be tested at least annually for impairment. ASC 350 also requires that long-lived assets be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable from its undiscounted future cash flow. See also “Item 5 — Operating and Financial Review and Prospects — A. Operating Results — Critical Accounting Policies and Estimates — Goodwill, Intangible Assets and Long-lived Assets.” For 2013, 2014 and 2015, we did not recognize any impairment charges for goodwill or intangible assets. If different judgments or estimates had been utilized, however, material differences could have resulted in the amount and timing of the impairment charge. We may potentially incur significant impairment charges if the recoverability of these assets become substantially reduced in the future.

In addition, our strategic acquisitions and investments could also subject us to other uncertainties and risks, and our failure to address any of these uncertainties and risks, among others, may have a material adverse effect on our financial condition and results of operations:

·                  diversion of our resources and management attention;

·high acquisition and financing costs;

·                  potential ongoing financial obligations and unforeseen or hidden liabilities;

·                  failure to achieve our intended objectives or benefits in making these investments or revenue-enhancing opportunities;

·                  cost of, and difficulties in, integrating acquired businesses and managing a larger business;

·                  failure to be in full compliance with applicable laws, rules and regulations;

·                  potential claims or litigation regarding our board’s exercise of its duty of care and other duties required under applicable law in connection with any of our significant acquisitions or investments approved by the board; and

·                  diversionfailure to be in full compliance with applicable laws, rules and regulations.

In particular, our strategy of acquiring or investing in a competing business could be adversely affected by uncertainties in the implementation and enforcement of the PRC Anti-Monopoly Law. Under the PRC Anti-Monopoly Law, companies undertaking acquisitions or investments in a business in China must notify the PRC Ministry of Commerce, or MOFCOM, in advance of any transaction where the parties’ revenues in the China market and global market exceed certain thresholds and the buyer would obtain control of, or decisive influence over, the target. There are numerous factors MOFCOM considers in determining “control” or “decisive influence,” and, depending on certain criteria, MOFCOM will conduct anti-monopoly review of transactions in respect of which it was notified. In light of the uncertainties relating to the interpretation, implementation and enforcement of the PRC Anti-Monopoly Law, we cannot assure you that MOFCOM will not deem our past and future acquisitions or investments, including the ones referenced herein or elsewhere in this annual report, to have met the filing criteria under the PRC Anti-Monopoly Law and therefore demand a filing for merger review. However, there have been limited cases of MOFCOM anti-monopoly review of filings involving companies with a “variable interest entity” structure, or VIE structure, similar to ours. If we are found to have violated the PRC Anti-Monopoly Law for failing to file the notification of concentration and request for review, we could be subject to a fine of up to RMB500,000, and the parts of the transaction causing the prohibited concentration could be ordered to be unwound. Such unwinding could affect our business and financial results, and harm our reputation. Further, if any of our resourcesbusiness cooperation arrangements with Qunar are determined to have violated the PRC Anti-Monopoly Law, we could be subject to sanctions including an order to cease the relevant activities, confiscation of illegal gains and management attention.fines of 1% to 10% of our sales revenue from the previous year.

In addition, we establish strategic alliances with various third parties to further our business purpose from time to time. Strategic alliances with third parties could subject us to a number of risks, including risks associated with sharing proprietary information, non-performance by the counter-party, an increase in expenses incurred in establishing new strategic alliances, inefficiencies caused by failure to integrate strategic partners’ businesses with our own, and unforeseen levels of diversion of our resources and management attention, any of which may materially and adversely affect our business.

From time to time, we selectively acquired or invested in businesses that complement our existing business, and will continue to do so in the future. See “Item 4. Information on the Company — A. History and Development of the Company” for more details of our acquisitions and investments. We cannot assure you that we will be able to achieve the benefits we expected from such acquisitions or investments. Moreover, our strategy of acquiring or investing in a competing business could be adversely affected by uncertainties in the implementation and enforcement of the PRC Anti-Monopoly Law. Under the PRC Anti-Monopoly Law, companies undertaking acquisitions or investments in a business in China must notify MOFCOM in advance of any transaction where the parties’ revenues in the China market and global market exceed certain thresholds and the buyer would obtain control of, or decisive influence over, the target. There are numerous factors MOFCOM considers in determining “control” or “decisive influence,” and, depending on certain criteria, MOFCOM will conduct anti-monopoly review of transactional transactions in respect of which it was notified. In light of the uncertainties relating to the interpretation, implementation and enforcement of the PRC Anti-Monopoly Law, there is no assurance that MOFCOM will not deem our past and future acquisitions or investments, including the ones referenced herein or elsewhere in this annual report, to have met the filing criteria under the PRC Anti-Monopoly Law and therefore demand a filing for merger review. However, there have been limited cases of MOFCOM anti-monopoly review of filings involving companies with a variable interest entity structure similar to ours. If we are found to have violated the PRC Anti-Monopoly Law for failing to file the notification of concentration and request for review, we could be subject to a fine of up to RMB500,000, and the parts of the transaction causing the prohibited concentration could be ordered to be unwound. Such unwinding could affect our business and financial results, and harm our reputation.

As a result of any of the above factors, any actual or perceived failure to realize the benefits we expected from these acquisitions or investments may materially and adversely affect our business and financial results and cause the trading price of our ADSs to decline.

OurIf Qunar fails to effectively implement and execute its strategies to maintain competitiveness and grow its business, could suffer if we do not successfully manage current growthor incur net loss in the future, our business, results of operations and potential future growth.financial condition may be materially and adversely affected.

OurAs a result of the transactions described elsewhere in this annual report involving Qunar securities during 2015, we began to consolidate Qunar’s financial results from December 31, 2015 from an accounting perspective under U.S. GAAP. Historically, Qunar enjoyed one of the market leading positions in China’s travel industry with its unique business model as a search-based travel commerce platform, while it is currently transitioning into a mobile and online commerce travel platform that focuses on providing users with one-stop solutions. Certain risks and uncertainties associated with the business operations of Qunar are distinct from those we have faced historically:

·                  Failure to transition into a one-stop mobile and online commerce travel platform from a search-based platform. As part of the transitioning effort, Qunar’s product development and product headcount has grownincreased significantly in recent years as a result of both organic growthits focus on development of existing operationsits mobile platform and acquisitions, and we expect to continue to experience such growth in the future. We have significantly expanded our operations and anticipate further expansion of our operations and workforce, as a result of the continued growth of our service offerings, customer base and geographic coverage. For example, we have invested in, and plan to continue to invest in, organic growth by rolling out new business initiatives focusing in a diverse range of areas including cruise lines, car services, bus tickets and train tickets, and if such new business initiatives fail to perform as expected, our financial condition and results of operations could be adversely impacted. Our growth to date has placed, and our anticipated future operations will continue to place, a significant strain on our management, systems and resources. In addition to training and managing our workforce, we will need to continue to improve and develop our financial and managerial controls and our reporting systems and procedures. We cannot assure you that we will be able to efficiently or effectively manage the growth of our operations, and any failure to do so may limit our future growth and hamper our business strategy.hotel direct business;

·                  Failure to increase penetration into hotel business in lower-tier cities, and maintain and increase popularity among young users in China by offering attractive features and services to meet user requirements of those markets;

·                  Failure to maintain relationships with air ticket suppliers, such as major airlines and China’s sole global distribution systems, from which Qunar retrieves ticket availability information in order to generate comprehensive and accurate flight information on its platform;

·                  Failure to maintain and strengthen relationships with online travel agents that are Qunar’s existing customers, and establish new customer relationships with other online travel agents and travel service providers to ensure that it has access to a steady supply of travel product information on favorable commercial terms;

·                  Failure to adequately monitor and secure service quality of travel service providers on its platform, and address user dissatisfaction with travel service providers;

·Consolidation of the results of operations of Qunar. Qunar with ours mayhistorically incurred net loss and our consolidation of Qunar’s financial statements had negatively impactimpacted our financial performance and results of operations.statements previously:

Following the consummation·                  Consolidation of the share exchange transaction with Baidufragmented travel market in October 2015, we beneficially owned approximately 45%China, which may result in travel service providers becoming fewer but larger, comprehensive travel information more readily available to users, and a potential loss to the value of Qunar’s aggregate voting interest. See “Item 4. Information on the Company — B. Business Overview — Strategic Investmentsbusiness as a travel service platform; and Acquisitions.” In connection with our transaction with Baidu, we agreed

·                  Inability to issue approximately 5 million ordinary shares to certain special purpose vehicles holding shares solely for the benefitmaintain or increase awareness and preference of Qunar employees. The issuance of such Ctrip shares to Qunar employees is conditional upon the surrender by such employees of any Qunar securities held by or granted to them. Thus far, we offered a total of approximately 4.0 million ordinary shares to three special purpose vehicles holding these shares solely for the benefit of Qunar employees. Future receipt by Qunar employees of Ctrip shares will be upon satisfaction of legal and contractual conditions. Asits brand “Qunar” as a result of these transactions, we accounted forfailure to provide a compelling user experience of online travel searches, maintaining the transactions as a business combination under U.S. GAAPquality of its services, and starting from December 31, 2015, we started to consolidatepreserving Qunar’s financial statements from the accounting perspective. Qunar has historically incurred net loss. Therefore, consolidating Qunar’s financial statements may negatively impact our financial performancereputation and goodwill in the upcoming financial reporting cycles for an extended periodevent of time. Moreover, startingnegative media publicity toward its services, internet security or other issues affecting Qunar or online travel businesses in January 2016, some PRC airlines, including two of the largest airlines in China, announced suspension of their respectiveChina.

If Qunar is unable to successfully implement and execute its strategies to maintain competitiveness and grow its business, cooperationor effectively address risks and uncertainties associated with Qunar without indicating the length of such suspensionits business operations and cited serious customer complaints in their respective announcements. If such suspension further exacerbates, Qunar may suffer from loss of revenue and itstransitioning efforts, our business, results of operations and financial condition may be materially and adversely affected, which in turn may materially and adversely affect our consolidated results of operations. The pro forma financial statements giving effect to this investment are incorporated by reference in this annual report.affected.

Our recent transactions including share exchange with Baidu,involving issuance of our shares for the benefit of Qunar employeesas consideration and investment or financing arrangements with selected third-party investment entities willmay result in substantial dilution to our shareholders and willmay also reduce our existing cash balance.balance and adversely affect our working capital.

In the long-term interest of our company, we will make investments, in the form of limited partnership contributions, assets injection or other financing arrangements, into or with certain entities that are dedicated to investing businesses in China. In late 2015 and early 2016, weWe agreed to make investmentcertain investments, in the form of limited partnership contribution or enter intoother financing arrangements, within several non-U.S. investment entities, whichamounting to an aggregate fair value of approximately US$2.9 billion and US$0.4 billion in 2016 and 2017. These entities are managed and/or owned by parties unaffiliated with each other and unaffiliated with us and are dedicated to investing in businesses in China. In January 2016,These investment entities have spent the proceeds of our investments to acquire the equity interest in Qunar that were not held by us through privately negotiated transactions. Under U.S. GAAP, we issued a total number of 5,431,983 ordinary shares, including 2,661,967 ordinary shares represented by ADSs, and provided capital contribution orconsolidate the financial support in a total amount of approximately US$1.3 billion in cash to somestatements of these non-U.S. investment entities. In March 2016, we further issued an aggregate of 474,534 ordinary shares represented by ADSs to certain of these non-U.S. investment entities and these ordinary shares represent approximately 1% of our immediate post-issuance outstanding shares.from an accounting perspective. These investments, capital contributions and financing arrangements in the form of our ordinary shares may result in our issuance of a substantial number of our ordinary shares in the aggregate, which together with the recent share exchange with Baidu and issuance of shares for the benefit of Qunar employees will causehistorically caused significant dilution to our existing shareholders and impacted our working capital. Transactions involving issuance of a substantial number of our ordinary shares such as the transactions contemplated hereunder may result in substantial dilution to our existing shareholders. In addition, future sale of our shares by Baiduthese non-U.S. investment entities and/or our other significant shareholders individually or in the aggregate,such as Baidu may cause our share price to decline. Furthermore, our cash investments or financial support in selected investment entities may materially reduce our existing cash balance and adversely affect our working capital. If we decide to raise additional capital through the sale of equity or equity linked securities, our existing shareholders will be further diluted. Ifif we obtain debt financings, we may be subject to restrictive covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. See “Item 4.4.B. Information on the Company — B. Company—Business Overview — Overview—Strategic Investments and Acquisitions.”

Our business is sensitive to global economic conditions. A severe or prolonged downturn in the global or Chinese economy may have a material and adverse effect on our business, and may materially and adversely affect our growth and profitability.

The global macroeconomic environment is facing challenges, including the escalation of the European sovereign debt crisis since 2011, the end of quantitative easing by the U.S. Federal Reserve, and the economic slowdown in the Eurozone in 2014.2014, and the slowdown of the Chinese economy since 2012. There have been concerns over unrest in the Middle East and Africa, which have resulted in volatility in oil and other markets, and over the expansion of terrorist activities into Europe and other regions. In June 2016, British citizens voted in a referendum to withdraw the membership of the United Kingdom from the European Union. The result of the vote caused instant and significant volatility in the global financial and securities markets. The various uncertainties in the political and economic situations of the United Kingdom and the European Union arising from the anticipated withdrawal may have a negative and prolonged impact on the global economy.

Economic conditions in China are sensitive to global economic conditions. Our business and operations are primarily based in China and the majority of our revenues are derived from our operations in China. Accordingly, our financial results have been, and are expected to continue to be, affected by the economy and travel industry in China. While the economy in China has grown significantly over the past decades, growth has been uneven, both geographically and among various sectors of the economy, and the rate of growth has been slowing. Any severe or prolonged slowdown in the global and/or Chinese economy could reduce expenditures for travel, which in turn may adversely affect our operating results and financial condition. According to the National Bureau of Statistics of China, in 2015, the growth rate of China’s gross domestic product, or GDP, was 6.9% and it is unclear how the economy will fare in 2016 and beyond. Since we derive the majority of our revenues from accommodation reservation, transportation ticketing and packaged-tour services in China, any severe or prolonged slowdown in the global and/or Chinese economy or the recurrence of any financial disruptions could reduce expenditures for travel, which in turn may materially and adversely affect our business operating results and financial condition in a number of ways. For example, the weakness in the economy could erode consumer confidence which, in turn, could result in changes to consumer spending patterns relating to travel products and services. If consumer demand for travel products and services we offer decreases, our revenues may decline. Furthermore, continued turbulence in the international markets may adversely affect our ability to access the capital markets to meet liquidity needs.

General declines or disruptions in the travel industry may materially and adversely affect our business and results of operations.

Our business is significantly affected by the trends that occur in the travel industry in China, including the hotel, transportation ticketing and packaged-tour sectors. As the travel industry is highly sensitive to business and personal discretionary spending levels, it tends to decline during general economic downturns. The recent worldwide recession has led to a weakening in the demand for travel services. Other trends or events that tend to reduce travel and are likely to reduce our revenues include:

·                  terrorist attacks or threats of terrorist attacks or wars, particularly given the recentterrorist attacks in Paris Belgium and the worsening situation in Syria;

·                  an outbreak of H1N1 influenza, Ebola virus, avian flu, Middle East respiratory syndrome, or MERS, severe acute respiratory syndrome, or SARS, or any other serious contagious diseases;

·                  increasedincreasing prices in the hotel, transportation ticketing, or other travel-related sectors;

·                  increasedincreasing occurrence of travel-related accidents;

·                  political unrest;

·                  natural disasters or poor weather conditions; and

·                  any travel restrictions or other security procedures implemented in connection with any major events in China.

We could be severely and adversely affected by declines or disruptions in the travel industry and, in many cases, have little or no control over the occurrence of such events. Such events could result in a decrease in demand for our travel services. This decrease in demand, depending on the scope and duration, could significantly and adversely affect our business and financial performance over the short and long term.

We recorded a significant amount of goodwill and indefinite lived intangible assets in connection with our strategic acquisitions and investments, and we may incur material impairment charges to our goodwill and indefinite lived intangible assets if the recoverability of these assets become substantially reduced.

In connection with our strategic acquisitions over the recent years, we recorded a significant amount of goodwill and indefinite lived intangible assets booked in our financial statements. As of December 31, 2017, our goodwill was RMB56.2 billion (US$8.6 billion) and our indefinite lived intangible assets were RMB11.8 billion (US$1.8 billion). In 2015, our acquisition of Qunar securities resulted in a RMB43.0 billion increase in our goodwill. ASC 350 “Intangibles—Goodwill and Other” provides that intangible assets that have indefinite useful lives and goodwill will not be amortized but rather will be tested at least annually for impairment. ASC 350 also requires that long-lived assets be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable from its undiscounted future cash flow. For 2015, 2016, and 2017, we did not recognize any impairment charges for goodwill or intangible assets. If different judgments or estimates had been utilized, however, material differences could have resulted in the amount and timing of the impairment charge. We may potentially incur significant impairment charges if the recoverability of these assets become substantially reduced in the future. Any such impairment charges would adversely affect our results of operations and financial condition.

The trading price of our ADSs has been volatile historically and may continue to be volatile regardless of our operating performance.

The trading pricesprice of our ADSs havehas been and may continue to be subject to wide fluctuations. In 2015,2017, the trading prices of our ADSs on the NASDAQNasdaq Global Select Market as adjusted retrospectively for all periods presented to reflect the current ADS to ordinary share ratio of eight (8) ADSs representing one ordinary share effective on December 1, 2015, have ranged from US$21.5440.40 to US$57.3660.65 per ADS, and the last reported trading price on April 21, 201620, 2018 was US$47.2142.65 per ADS. The price of our ADSs may fluctuate in response to a number of events and factors, including the following:

·                  actual or anticipated fluctuations in our quarterly operating results;

·                  changes in financial estimates by securities analysts;

·                  conditions in the Internet or travel industries;

·                  changes in the economic performance or market valuations of other Internet or travel companies or other companies that primarily operate in China;

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·                  changes in major business terms between our travel suppliers and us;

·                  announcements by us or our competitors of new products or services, significant acquisitions, strategic partnerships, joint ventures, or capital commitments;

·                  negative publicity in connection with our business operation;

·additions or departures of key personnel; and

·                  market and volume fluctuations in the stock market in general.

In addition, the stock market in general, and the market prices for Internet-related companies and companies with operations in China in particular, have experienced volatility that often has been unrelated to the operating performance of such companies. The securities of some China-based U.S.-listed companies that have listed their securities in the United States have experienced significant volatility since their initial public offerings, including, in some cases, substantial price declines in the trading prices of their securities. The trading performancesperformance of the securities of these China-based U.S.-listed companies after their offerings and the recent surge in the number of China-based U.S.-listed companies that commenced going privategoing-private proceedings in recent years may affect the attitudes of investors toward ChineseChina-based U.S.-listed companies, listed in the United States, which consequently may impact the trading performance of the ADSs, regardless of our actual operating performance. Furthermore, some negative news and perceptions about inadequate corporate governance practices or fraudulent accounting, corporate structure including the use of variable interest entitiesVIE structures or other matters of other China-based U.S.-listed companies have negatively affected the attitudes of investors towards China-based U.S.-listed companies, including us, in general in the past, regardless of whether we have engaged in any inappropriate activities, and any news or perceptions with a similar nature may continue to negatively affect us in the future. In addition, the global financial crisis and the ensuing economic recessions in many countries have contributed and may continue to contribute to extreme volatility in the global stock markets, such as the large decline in share prices in the United States, China and other jurisdictions in recent years. These broad market and industry fluctuations may continue to adversely affect the trading price of the ADSs, regardless of our operating performance. Additionally, volatility or a lack of positive performance in our stockADS price may adversely affect our ability to retain key employees, all of whom have been granted share-based awards.

If we are unable to maintain existing relationships with travel suppliers and strategic alliances, or unable to establish new arrangements with travel suppliers and strategic alliances at or on favorable terms or at terms similar to those we currently have, or at all, our business, market share and results of operations may be materially and adversely affected.

We rely on travel suppliers (including without limitation hotels and domestic and international airlines) to make their services available to consumers through us, and our business prospects depend on our ability to maintain and expand relationships with travel suppliers. If we are unable to maintain satisfactory relationships with our existing travel suppliers, or if our travel suppliers establish similar or more favorable relationships with our competitors, or if our travel suppliers increase their competition with us through their direct sales, or if any one or more of our travel suppliers significantly reduce participation in our services for a sustained period of time or completely withdraw participation in our services, our business, market share and results of operations may be materially and adversely affected. To the extent any of those major or popular travel suppliers ceased to participate in our services in favor of one of our competitors’ systems or decided to require consumers to purchase services directly from them, our business, market share and results of operations may suffer.

Our business depends significantly upon our ability to contract with hotels in advance for the guaranteed availability of certain hotel rooms. We rely on hotel suppliers to provide us with rooms at discounted prices. However, our contracts with our hotel suppliers are not exclusive and most of the contracts must be renewed semi-annually or annually. We cannot assure you that our hotel suppliers will renew our contracts in the future on favorable terms or terms similar to those we currently have agreed. The hotel suppliers may reduce the commission rates on bookings made through us. Furthermore, in order to maintain and grow our business and to effectively compete with many of our competitors in all potential markets, we will need to establish new arrangements with hotels and accommodations of all ratings and categories in our existing markets and in new markets. We cannot assure you that we will be able to identify appropriate hotels or enter into arrangements with those hotels on favorable terms, if at all. This failure could harm the growth of our business and adversely affect our operating results and financial condition, which consequently will impact the trading price of our ADSs.

We derive revenues and other significant benefits from our arrangements with major domestic airlines in China and international airlines. Our airline ticket suppliers allow us to book and sell tickets on their behalf and collect commissions on tickets booked and sold through us. Although we currently have supply relationships with these airlines, they also compete with us for ticket bookings and have entered into similar arrangements with many of our competitors and may continue to do so in the future. Such arrangements may be on better terms than we have. In the past, airlines have from time to time reduced the commission rates on tickets booked and sold through us, which negatively affected our revenues from transportation ticketing in the relevant periods. Starting in Januaryearly 2016, some PRC airlines, including twofour of the largest airlines in China, announced suspension of their respective business cooperation with Qunar without indicating the length of such suspension and cited serious customer complaints in their respective announcements. Although we are not awaremost of anythese airlines publicly announcing suspension of businesshave resumed cooperation with us as of the date of this annual report,Qunar, if any airlines choose to take similar actions against us and additional airlines follow suit, our business, market share and results of operations may be materially and adversely affected. We cannot assure you that any of these airlines will continue to have supplier relationships with us or pay us commissions at the same or similar rates as what they paid us in the past. Further, on July 1, 2016, the four largest airlines in China announced that third-party ticketing agents are prohibited from selling tickets for domestic flights on third-party platforms, such as ours. Additionally, on July 1, 2016, most major domestic airlines also replaced their commissions and rebate incentives completely with a reduced, fixed “admin fee” per ticket. The loss of these supplier relationships or further adverse changes in major business terms with our travel suppliers would materially impair our operating results and financial condition as we would lose an increasingly significant source of our revenues.

Part of the revenues that we derive from our hotel suppliers, airline ticket suppliers and other travel service providers are obtained through our strategic alliances with various third parties. We cannot assure you, however, that we will be able to successfully establish and maintain strategic alliances with third parties which are effective and beneficial for our business. Our inability to do so could have a material adverse effect on our market penetration, revenue growth and profitability.

If we fail to further increase our brand recognition, we may face difficulty in maintaining existing and acquiring new customers and business partners and our business may be harmed.

We believe that maintaining and enhancing the Ctrip brand depends in part on our ability to grow our customer base and obtain new business partners. Some of our potential competitors already have well-established brands in the travel industry. The successful promotion of our brand will depend largely on our ability to maintain a sizeable and active customer base, maintain relationships with our business partners, provide high-quality customer service, properly address customer needs and handle customer complaints and organize effective marketing and advertising programs. If our customer base significantly declines or grows more slowly than our key competitors, the quality of our customer services substantially deteriorates, or our business partners cease to do business with us, we may not be able to cost-effectively maintain and promote our brand, and our business may be harmed.

If we do not compete successfully against new and existing competitors, we may lose our market share, and our business may be materially and adversely affected.

We compete primarily with other consolidators of hotel accommodations and transportation reservation services based in China, such as Qunar and eLong.China. We also compete with traditional travel agencies and new Internet travel search websites. In the future, we may also face competition from new players in the hotel consolidation market in China and abroad that may enter China.

We may face more competition from hotels and airlines as they enter the discount rate market directly or through alliances with other travel consolidators. In addition, international travelers have become an increasingly important customer base. Competitors that have formed stronger strategic alliances with overseas travel consolidators may have more effective channels to address the needs of customers in China to travel overseas. Furthermore, we do not have exclusive arrangements with our travel suppliers. The combination of these factors means that potential entrants to our industry face relatively low entry barriers.

In the past, certain competitors launched aggressive advertising campaigns, special promotions and engaged in other marketing activities to promote their brands, acquire new customers or to increase their market shares. In response to such competitive pressure, we started to take and may continue to take similar measures and as a result will incur significant expenses, which in turn could negatively affect our operating margins in the quarters or years when such promotional activities are carried out. For example, we launched a promotion program in recent years to offer certain selected transportation tickets, hotel rooms and package tours as well as grant of e-coupons to our customers in response to promotion campaigns that our competitors have launched. Primarily as a result of the enhanced marketing efforts and additional investment in product developments in response to the intensified market competition, our operational margin was negatively affected. In addition, some of our existing and potential competitors may have competitive advantages, such as significantly larger active user base on mobile or other online platforms, greater financial, marketing and strategic relationships and alliances or other resources or name recognition, and may be able to imitate and adopt our business model. We cannot assure you that we will be able to successfully compete against new or existing competitors. In the event we are not able to compete successfully, our business, results of operations and profit margins may be materially and adversely affected.

Our quarterly results are likely to fluctuate because of seasonality in the travel industry in Greater China.

Our business experiences fluctuations, reflecting seasonal variations in demand for travel services. For example, the first quarter of each year generally contributes the lowest portion of our annual net revenues primarily due to a slowdown in business activity around and during the Chinese New Year holiday, which occurs during the period. Consequently, our results of operations may fluctuate from quarter to quarter.

Any failure to maintain the satisfactory performance of our mobile platform, websites, and systems, particularly those leading to disruptions in our services, could materially and adversely affect our business and reputation, and our business may be harmed if our infrastructure or technology is damaged or otherwise fails or becomes obsolete.

The satisfactory performance, reliability and availability of our infrastructure, including our mobile platform, websites, and systems, are critical to the success of our business. Any system interruptions that result in the unavailability or slowdown of our mobile platform, websites or other systems and the disruption in our services could reduce the volume of our business and make us less attractive to customers. Substantially all of our computer and communications systems are located at two customer service centers, one in Shanghai, China and the other one in Nantong, China. Our technology platform and computer and communication systems are vulnerable to damage or interruption from human error, computer viruses, fire, flood, power loss, telecommunications failure, physical or electronic break-ins, hacking or other attempts at system sabotage, vandalism, natural disasters, and other similar events. For example, in May 2015, we experienced a network shut-down for a few hours, leading to temporary disruptions in the operations of our mobile platform and websites and interrupted customer services; later internal investigations revealed the cause to be employee human error. No data leakage occurred as part of the May 2015 incident, and we have since implemented extensive measures to ensure prompt responses to similar future incidents of network shutdown/service disruption and to continue to update our security mechanisms to protect our systems from any human error, third-party intrusions, viruses or hacker attacks, information or data theft or other similar activities; however, we cannot assure you that unexpected interruptions to our systems will not occur again in the future. We do not carry business interruption insurance to compensate us for losses that may occur as a result of such disruptions. In addition, any such future occurrences could reduce customer satisfaction levels, damage our reputation and materially and adversely affect our business.

We use an internally developed booking software system that supports nearly all aspects of our booking transactions. Our business may be harmed if we are unable to upgrade our systems and infrastructure quickly enough to accommodate future traffic levels, avoid obsolescence or successfully integrate any newly developed or purchased technology with our existing system. Capacity constraints could cause unanticipated system disruptions, slower response times, poor customer service, impaired quality and speed of reservations and confirmations and delays in reporting accurate financial and operating information. These factors could cause us to lose customers and suppliers, which would have a material adverse effect on our results of operations and financial condition.

In addition, our future success will depend on our ability to adapt our products and services to the changes in technologies and Internet user behavior. For example, the number of people accessing the internetInternet through mobile devices, including smart devices, mobile phones, tablets and other hand-held devices, has increased in recent years, and we expect this trend to continue while 3G, 4G and more advanced mobile communications technologies are broadly implemented. As we make our services available across a variety of mobile operating systems and devices, we are dependent on the interoperability of our services with popular mobile devices and mobile operating systems that we do not control, such as Android, iOS and Windows. Any changes in such mobile operating systems or devices that degrade the functionality of our services or give preferential treatment to competitive services could adversely affect usage of our services. Further, if the number of platforms for which we develop our services increases, which is typically seen in a dynamic and fragmented mobile services market such as China, it will result in an increase in our costs and expenses. In order to deliver high quality services, it is important that our services work well across a range of mobile operating systems, networks, mobile devices and standards that we do not control. If we fail to develop products and technologies that are compatible with all mobile devices and operating systems, or if the products and services we develop are not widely accepted and used by users of various mobile devices and operating systems, we may not be able to penetrate the mobile Internet market. In addition, the widespread adoption of new internetInternet technologies or other technological changes could require significant expenditures to modify or integrate our products or services. If we fail to keep up with these changes to remain competitive, our future success may be adversely affected.

Our business depends substantially on the continuing efforts of our key executives, and our business may be severely disrupted if we lose their services.

Our future success depends heavily upon the continued services of our key executives. We rely on their expertise in business operations, finance and travel services and on their relationships with our suppliers, shareholders, and business partners. We do not maintain key-man life insurance for any of our key executives. If one or more of our key executives are unable or unwilling to continue in their present positions, we may not be able to easily replace them. In that case, our business may be severely disrupted, we may incur additional expenses to recruit and train personnel and our financial condition and results of operations may be materially and adversely affected.

In addition, if any of these key executives joins a competitor or forms a competing company, we may lose customers and suppliers. Each of our executive officers has entered into an employment agreement with us that contains confidentiality and non-competition provisions. If any disputes arise between our executive officers and us, we cannot assure you of the extent to which any of these agreements would be enforced in China, where most of these executive officers reside and hold most of their assets, in light of the uncertainties with China’s legal system. See “— “Item 3.D. Key Information—Risk Factors—Risks Related to Doing Business in China — China—Uncertainties with respect to the PRC legal system could adversely affect us.”

If we are unable to attract, train and retain key individuals and highly skilled employees, our business may be adversely affected.

If our business continues to expand, we will need to hire additional employees, including travel supplier management personnel to maintain and expand our travel supplier network, information technology and engineering personnel to maintain and expand our mobile platform, websites, customer service centers, and systems, and customer service representatives to serve an increasing number of customers. If we are unable to identify, attract, hire, train, and retain sufficient employees in these areas, users of our mobile platform, websites, and customer service centers may not have satisfactory experiences and may turn to our competitors, which may adversely affect our business and results of operations.

The PRC government regulates the air-ticketing, travel agency, and Internet industries. If we fail to obtain or maintain all pertinent permits and approvals or if the PRC government imposes more restrictions on these industries, our business may be adversely affected.

The PRC government regulates the air-ticketing, travel agency, and Internet industries. We are required to obtain applicable permits or approvals from different regulatory authorities to conduct our business, including separate licenses for value-added telecommunications, air-ticketing, and travel agency and Internet-related activities. If we fail to obtain or maintain any of the required permits or approvals in the future, we may be subject to various penalties, such as fines or suspension of operations in these regulated businesses, which could severely disrupt our business operations. As a result, our financial condition and results of operations may be adversely affected.

In particular, the Civil Aviation Administration of China, or CAAC, together with National Development and Reform Commission, or NDRC, regulates pricing of air tickets. CAAC also supervises commissions payable to air-ticketing agencies together with China National Aviation TransportationAir Transport Association, or CNATA.CATA. If restrictive policies are adopted by CAAC, NDRC, or CNATA,CATA, or any of their regional branches, our air-ticketing revenues may be adversely affected.

We may not be able to prevent others from using our intellectual property, which may harm our business and expose us to litigation.

We regard our domain names, trade names, trademarks and similar intellectual property as critical to our success. We try to protect our intellectual property rights by relying on trademark protection and confidentiality laws and contracts. Trademark and confidentiality protection in China may not be as effective as that in the United States. Policing unauthorized use of proprietary technology is difficult and expensive.

The steps we have taken may be inadequate to prevent the misappropriation of our proprietary technology. Any misappropriation could have a negative effect on our business and operating results. Furthermore, we may need to go to court to enforce our intellectual property rights. Litigation relating to our intellectual property might result in substantial costs and diversion of resources and management attention. See “—“Item 3.D. Key Information — Risk Factors — Risks Related to Doing Business in China — Uncertainties with respect to the PRC legal system could adversely affect us.”

We rely on services from third parties to carry out our business and to deliver our products to customers, and if there is any interruption or deterioration in the quality of these services, our customers may not continue using our services.

We rely on third-party computer systems to host our websites, as well as third-party licenses for some of the software underlying our technology platform. In addition, we rely on third-party transportation ticketing agencies to issue transportation tickets and travel insurance products, confirmations and deliveries in some cities in Greater China. We also rely on third-party local operators to deliver on-site services to our packaged-tour customers. Any interruption in our ability to obtain the products or services of these or other third parties or deterioration in their performance, such as server errors or interruptions, or dishonest business conduct, could impair the timing and quality of our own service. If our service providers fail to provide high quality services in a timely manner to our customers or violate any applicable rules and regulations, our services will not meet the expectations of our customers and our reputation and brand will be damaged. Furthermore, if our arrangement with any of these third parties is terminated, we may not find an alternative source of support on a timely basis or on favorable terms to us.

If our hotel suppliers or customers provide us with untrue information regarding our customers’ stay, we may not be able to recognize and collect revenues to which we are entitled.

A substantial portion of our revenues are represented by commissions paid by hotels for room nights booked through us. Generally, we do not receive payment from our customers on behalf of our hotel suppliers, as our customers pay hotels directly. To confirm whether a customer adheres to the booked itinerary, we routinely make inquiries with the hotel and, occasionally, with the customer. We rely on the hotel and the customer to provide us truthful information regarding the customer’s check-in and check-out dates, which forms the basis for calculating the commission we are entitled to receive from the hotel. If our hotel suppliers or customers provide us with untrue information with respect to our customers’ length of stay at the hotels, we would not be able to collect revenues to which we are entitled. In addition, using such untrue information may lead to inaccurate business projections and plans, which may adversely affect our business planning and strategy.

We may suffer losses if we are unable to predict the amount of inventory we will need to purchase during the peak holiday seasons.

During the peak holiday seasons in China, we establish limited merchant business relationships with selected travel service suppliers, particularly for our packaged-tour products, in order to secure adequate supplies for our customers. In the merchant business relationship,relationships, we buy hotel rooms and/or transportation tickets before selling them to our customers and thereby incur inventory risk. If we are unable to correctly predict demand for hotel rooms and transportation tickets that we are committed to purchase, we would be responsible for covering the cost of the hotel rooms and transportation tickets we are unable to sell, and our financial condition and results of operations would be adversely affected.

The recurrence of SARS or other similar outbreaks of contagious diseases as well as natural disasters may materially and adversely affect our business and operating results.

In early 2003, several regions in Asia, including Hong Kong and China, were affected by the outbreak of SARS. The travel industry in China, Hong Kong and some other parts of Asia suffered tremendously as a result of the outbreak of SARS. Furthermore, in early 2008, severe snowstorms hit many areas of China and particularly affected southern China. The travel industry was severely and adversely affected during and after the snowstorms. Additionally, in May 2008, a major earthquake struck China’s populous Sichuan Province, causing great loss of life, numerous injuries, property loss and disruption to the local economy. The earthquake had an immediate impact on our business as a result of the sharp decrease in travel in the relevant earthquake-affected areas in Sichuan Province. In 2009, an outbreak of H1N1 influenza (swine flu) occurred in Mexico and the United States and human cases of the swine flu were discovered in China and Hong Kong. In March 2011, a powerful earthquake hit Japan, and the subsequent tsunami and nuclear accidents had far-reaching impact on the surrounding economies. Starting from March 2013, H7N9 bird flu, a new strain of animal influenza, has been spreading in China and has infected more than a hundred people. In October 2013, large scale political protests began in Thailand that lasted several months and caused disruption to tourism and travel. In November 2013, one of the largest typhoons ever recorded hit the Philippines, causing widespread devastation. In March 2014, the World Health Organization or the WHO, reported a major Ebola outbreak in Guinea, a western African nation. The disease then rapidly spread to the neighboring countries of Liberia and Sierra Leone. As of February 3, 2015, 22,560 suspected cases and 9,019 deaths had been reported; however, the WHOWorld Health Organization has said that these numbers may be underestimated. In June 2015, an outbreak of Middle East respiratory syndrome, or MERS, affected South Korea, one of our popular overseas travel destinations.

Any future outbreak of contagious diseases, extreme unexpected bad weather or natural disasters would adversely affect our business and operating results. Ongoing concerns regarding contagious disease or natural disasters, particularly its effect on travel, could negatively impact our customers’ desire to travel. If there is a recurrence of an outbreak of certain contagious diseases or natural disasters, travel to and from affected regions could be curtailed. Government advice regarding, or restrictions on, travel to and from these and other regions on account of an outbreak of any contagious disease or occurrence of natural disasters may have a material adverse effect on our business and operating results.

If tax benefits available to our subsidiaries in China are reduced or repealed, our results of operations could suffer.

Under the PRC Enterprise Income Tax Law and the relevant implementation rules, or the EIT Law, effective on January 1, 2008, foreign investedforeign-invested enterprises, or FIEs, and domestic enterprises are subject to EIT at a uniform rate of 25%. Certain enterprises will benefit from a preferential tax rate of 15% under the EIT Law if they qualify as “high and new technology enterprises,” or HNTEs, or if they are located in applicable PRC regions as specified in the Catalogue of Encouraged Industries in Western Regions, or the Western Regions Catalogue, subject to certain general restrictions described in the EIT Law and the related regulations.

In December 2008 and 2009, some of our PRC subsidiaries, Ctrip Computer Technology, Ctrip Travel Information, Ctrip Travel Network and JointWisdomQunar Software, and one of our consolidated affiliated Chinese entities, Qunar Beijing, were each designated by relevant local authorities as a “high and new technology enterprise”HNTE under the EIT Law with an effective period of three years. Therefore, these entities were entitled to enjoy a preferential tax rate of 15%, as long as they maintained their qualifications for “high and new technology enterprises”HNTEs that are subject to verification by competent authorities and renewals every three years with the current effective period expiringyears. The qualifications of these entities as HNTEs have been renewed and would expire by the end of 2017.2018 or 2020. We cannot assure you that our subsidiaries and the consolidated affiliated Chinese entity will continue to qualify as high and new technology enterprisesHNTEs when they are subject to reevaluation in the future. In 2002, the PRC State Administration of Taxation, or the SAT, started to implement preferential tax policy in China’s western region, and companies located in applicable jurisdictions covered by the Catalogue of Encouraged Industries in the Western Region (initially effective through the end of 2010 and further extended to 2020)Regions Catalogue are eligible to apply for a preferential income tax rate of 15% if their businesses fall within the “encouraged” category of the policy.policy and the revenue derived from such “encouraged” businesses accounts for more than 70% of the total revenue. Benefiting from this policy, Chengdu Ctrip and Chengdu Ctrip International obtained approval from local tax authorities to apply the 15% tax rate for their annual tax filing subject to periodic renewals over the years since 2012. The two entities re-applied for this qualification afterAfter the initial effective period expired in 2014, and their applicationsthe two entities were approved by the relevant government authority. to renew this qualification, which will expire in 2020. In 2013, Chengdu Information Technology Co., Ltd., or Chengdu Information, obtained approval from local tax authorities to apply the 15% tax rate for its 2012 tax filing and for the years from 2013 to 2016.2020. In the event that the preferential tax treatment for these entities is discontinued, these entities will become subject to the standard tax rate at 25%, which would materially increase our tax obligations.

We have sustained losslosses in the past and may experience earnings declinedeclines or net losslosses in the future.

We sustained net losslosses in certain past periods, and we cannot assure you that we can sustain profitability or avoid net losslosses in the future. We expect that our operating expenses will increase and the degree of increase in these expenses is largely based on anticipated growth, revenue trends and competitive pressure. As a result, any decrease or delay in generating additional sales volume and revenues and increase in our operating expenses may result in substantial operating losses. Moreover, consolidation of Qunar’s financial statements starting from December 31, 2015 had negatively impacted our financial statements previously, which may happen again in the future. See “Item 3.D. Key Information—Risk Factors—Risks Relating to Our Company—Consolidation of the results of operations of Qunar with ours may negatively impact our financial performance and results of operations.”

We have incurred substantial indebtedness and may incur additional indebtedness in the future. We may not be able to generate sufficient cash to satisfy our outstanding and future debt obligations.

As of December 31, 2015,2017, our total short-term bank borrowings and long-term bank borrowings (current portions) were RMB12.7RMB8.7 billion (US$21.3 billion), and our total long-term borrowings (excluding current portions) were RMB18.5RMB8.8 billion (US$2.851.4 billion), and the aggregate principal amount of our outstanding convertible notes was RMB28.1 billion (US$4.3 billion). To the extent that we were to settle or redeem our convertible notes in cash, our debt obligations would become more substantial.

Our substantial indebtedness could have important consequences to you. For example, it could:

·                  increase our vulnerability to adverse general economic and industry conditions;

·                  require us to dedicate a substantial portion of our cash flow from operations to servicing and repaying our indebtedness, thereby reducing the availability of our cash flow to fund working capital, capital expenditures and other general corporate purposes; and

·                  limit, along with the financial and other restrictive covenants of our indebtedness, among other things, our ability to conduct additional financing activities, or increase the cost of additional financing.

In the future, we may from time to time incur additional indebtedness and contingent liabilities. If we incur additional debt, the risks that we face as a result of our substantial indebtedness and leverage could intensify.

Our ability to generate sufficient cash to satisfy our outstanding and future debt obligations will depend upon our future operating performance, which will be affected by prevailing economic conditions and financial, business and other factors, many of which are beyond our control. As a result, we may not generate or obtain sufficient cash flow to meet our anticipated operating expenses and to service our debt obligation as they become due.

We may be subject to legal or administrative proceedings regarding information provided on our online portals or other aspects of our business operations, which may be time-consuming to defend.

Our online portals contain information about hotels, transportation, popular vacation destinations, and other travel-related topics. It is possible that if any information accessible on our online portals contains errors or false or misleading information, third parties could take action against us for losses incurred in connection with the use of such information. From time to time, we have become and may in the future become a party to various legal or administrative proceedings arising in the ordinary course of our business, including actions with respect to labor and employment claims, breach of contract claims, anti-competition claims, and other matters. Although such proceedings are inherently uncertain and their results cannot be predicted with certainty, we believe that the resolution of our current pending matters will not have a material adverse effect on our business, consolidated financial position, results of operations, or cash flow. Regardless of the outcome and merit of such proceedings, however, any legal action can have an adverse impact on us because of defense costs, negative publicity, diversion of management’s attention, and other factors. In addition, it is possible that an unfavorable resolution of one or more legal or administrative proceedings, whether in the PRCChina or in another jurisdiction, could materially and adversely affect our financial position, results of operations or cash flows in a particular period or damage our reputation.

We could be liable for breaches of Internet security or fraudulent transactions by users of our mobile platform and our websites.

The Internet industry is facing significant challenges regarding information security and privacy, including the storage, transmission and sharing of confidential information. In recent years, PRC government authorities have enacted legislation on Internet use to protect personal information from any unauthorized disclosure. See “Item 4.4.B. Information on the Company — B. Company—Business Overview — Overview—PRC Government Regulations — Regulations—Internet Privacy.” We conduct a significant portion of our transactions through the Internet,, including our mobile platform and websites. In such transactions, secured transmission of confidential information (such as customers’ itineraries, hotel and other reservation information, credit card information, personal information, and billing addresses) over public networks and ensuring the confidentiality, integrity, availability, and authenticity of the information of our users, customers, hotel suppliers, and airline partners are essential to maintaining their confidence in our online products and services. Our current security measures may not be adequate and may contain deficiencies that we fail to identify, and advances in technology, increased levels of expertise of hackers, new discoveries in the field of cryptography or others could increase our vulnerability. For example, a third-party website with focus on Internet security information exchange released a news in March 2014 that as a result of a temporary testing function performed by us, certain data files containing customers’ credit card information had been stored on local servers maintained by us, which may lead to potential exposure of these customers’ information to hackers. We removed the cause of the potential security concern within two hours of the release of the news report and then examined all other possible leaks and found that 93 customers’ credit card information might have been downloaded by the above-mentioned website for the purpose of confirming potential risks. Although to our knowledge, no customer has suffered financial loss or other damage due tofrom the incident as of the date of thisthat report, our business, results of operations, user experience, and reputation may be materially and adversely affected if similar incidents related to Internet security recur in the future. In August 2011, China’sthe PRC Supreme People’s Court and the PRC Supreme People’s Procuratorate issued judicial interpretations regarding hacking and other Internet crimes. However, its effect on curbing hacking and other illegal online activities still remains to be seen.

Significant capital, managerial and human resources are required to enhance information security and to address any issues caused by security failures. If we are unable to protect our systems and the information stored in our systems from unauthorized access, use, disclosure, disruption, modification or destruction, such problems or security breaches may cause loss, expose us to litigation and possible liability to the owners of confidential information, disrupt our operations and may harm our reputation and ability to attract customers.

Our failure to comply with privacy and data protection laws and regulations in various jurisdictions could subject us to sanctions, damages, and litigation, and could harm our reputation and business.

We collect and process certain personal data of our users, including email addresses, usage data, identification information, user passwords, and additional information. We also collect and process user billing information, such as credit card numbers, full names, billing addresses, and phone numbers of our users.

We are subject to the privacy and data protection laws and regulations in various jurisdictions, including China, European Union, and Korea. Privacy laws provide restrictions and guidance in connection with our storage, use, processing, disclosure, transfer, and protection of personal information. We strive to comply with all applicable laws, regulations, policies relating to privacy and data protection. We are also subject to privacy and data security-related obligations deriving from our privacy policy and terms of use with our users, and we may be liable to third parties in the event we are deemed wrongfully processed personal data.

European Union traditionally takes a broader view as to what is considered personal information and has imposed greater obligations under their privacy and data protection laws. In particular, the European Union adopted a new General Data Protection Regulation in April 2016, which will become effective in May 2018. The General Data Protection Regulation will result in more stringent requirements for data processors and controllers, including more fulsome disclosures about the processing of personal information, data retention limits, and deletion requirements, mandatory notification in the case of a data breach, and elevated standards regarding valid consent in some specific cases of data processing. The General Data Protection Regulation also includes substantially higher penalties for failure to comply with the requirements. For example, in the event of violations, a fine up to €20 million or up to 4% of the annual worldwide turnover, whichever is greater, may be imposed. When General Data Protection Regulation and other future laws and regulations come into effect, the more stringent requirements on privacy user notifications and data handling will require us to adapt our business and incur additional costs.

Privacy concerns are becoming more widely acknowledged and may cause our users to resist providing the personal data necessary to allow them to use our platform effectively. We have implemented multiple measures and security protocols to maintain and improve our privacy protection capability. However, measures we have implemented may not alleviate all potential privacy concerns and threats. In addition, a failure by us or a third-party contractor providing services to us to comply with applicable privacy and data security laws, regulations, obligations, or our terms of use with our users, may result in sanctions, statutory or contractual damages or litigation. These violations or proceedings may, among other things, force us to spend money in defense or settlement, result in the imposition of monetary liability or restrict access to our services from certain territory, which could adversely affect our reputation and business.

Negative publicity with respect to us or the travel industry in general could impair our reputation, which in turn could materially and adversely affect our business, results of operations, and price of ADSs.

Negative publicity with respect to us or the travel industry in general could impair our reputation. Prospective customers may be prevented from engaging in transactions with us if there is any negative publicity in connection with the use of our services or products, the operation of our business, and other aspects about us. Furthermore, negative publicity about other market players or isolated incidents, whether or not factually correct, may result in negative perception of our industry as a whole and undermine the credibility we have established. Negative developments in the market may lead to tightened regulatory scrutiny and limit the scope of our permissible business activities. We could lose significant number of customers due to negative publicity with respect to us or the travel industry in general, which could materially and adversely affect our business, results of operations, and price of ADSs.

We may be the subject of detrimental conduct by third parties, including complaints to regulatory agencies, negative blog postings, and the public dissemination of malicious assessments of our business, which could have a negative impact on our reputation and cause us to lose market share, travel suppliers, and customers and revenues, and adversely affect the price of our ADSs.

We may be the target of anti-competitive, harassing, or other detrimental conduct by third parties. Such conduct may include complaints, anonymous or otherwise, to regulatory agencies regarding our operations, accounting, revenues, business relationships, business prospects and business ethics. Additionally, allegations, directly or indirectly against us, may be posted in Internet chat-rooms or on blogs or any websites by anyone, whether or not related to us, on an anonymous basis. We may be subject to government or regulatory investigation as a result of such third-party conduct and may be required to expendspend significant time and incur substantial costs to address such third-party conduct, and there is no assurancewe cannot assure you that we will be able to conclusively refute each of the allegations within a reasonable period of time, or at all. Our reputation may also be negatively affected as a result of the public dissemination of anonymous allegations or malicious statements about our business, which in turn may cause us to lose market share, travel suppliers and customers and revenues and adversely affect the price of our ADSs.

We have limited business insurance coverage in Greater China.

Insurance companies in Greater China offer limited business insurance products and generally do not, to our knowledge, offer business liability insurance. Business disruption insurance is available to a limited extent in Greater China, but we have determined that the risks of disruption, the cost of such insurance and the difficulties associated with acquiring such insurance make it impractical for us to have such insurance. We do not maintain insurance coverage for any kinds of business liabilities or disruptions and would have to bear the costs and expenses associated with any such events out of our own resources.

We hire celebrities to be our brand ambassadors to market our brands and products and this marketing initiative may not be effective.

From time to time, we hire celebrities to be our brand ambassadors to market our “Ctrip” brand or our products and services that are important to our business. However, we cannot give assuranceassure you that the endorsement from our brand ambassadors or related advertisements will remain effective, that the brand ambassadorambassadors will remain popular or his or hertheir images will remain positive and compatible with the messages that our brand and products aim to convey. Furthermore, we cannot ensureassure you that we can successfully find suitable celebrities to replace any of our existing brand ambassadorambassadors if any of histheir popularities declinesdecline or if the existing brand ambassador isambassadors are no longer able or suitable to continue the engagement, and termination of such engagements may have a significant impact on our brand images and the promotion or sales of our products. If any of these situations occurs, our business, financial condition and results of operations could be materially and adversely affected.

We may face greater risksrisk of doubtful accounts as our business increases in scale.

Since we began providing travel booking servicesWe provide credit terms to corporateour merchant customers, and some hotel customers who generally requestalso extend credit terms,to our users by making payments on behalf of them when they book travel products on our platform. Our accounts receivable and other receivable have increased.increased as our business grows. We cannot assure you that we will be able to collect payment fully and in a timely manner on our outstanding accounts receivablereceivables from our customers.merchant customers and users. As a result, we may face a greater risk of non-payment of our accounts receivable. For the years ended December 31, 2013, 2014receivables and, 2015, we recognized the provisions of doubtful accounts of RMB2.8 million, RMB11.7 million and RMB32.1 million (US$5.0 million) respectively. Asas our corporate travel business grows in scale, we may need to make increasedhigher provisions for doubtful accounts. For the years 2015, 2016 and 2017, we recognized the provisions for accounts receivables of approximately RMB32 million, RMB32 million, and RMB98 million (US$15 million), respectively, while the provisions for other receivable were immaterial. Our operating results and financial condition may be materially and adversely affected if we are unable to successfully manage our accounts receivable.receivables.

As we have commencedOur accounting treatment for employee share options using the fair value method beginning in 2006, such accounting treatmentshare-based compensation could continue to significantly reduce our net income.

Since 2006, we have accounted for share-based compensation in accordance with ASC 718 “Compensation — Stock Compensation,” or ASC 718, which requires a public company to recognize, as an expense, the fair value of share options and other share-based compensation to employees based on the requisite service period of the share-based awards. We have granted share-based compensation awards, including share options and restricted share units, to employees, officers and directors to incentivize performance and align their interests with ours. We have adopted four share incentive plans, namely, the 2007See “Item 6.B. Directors, Senior Management and Employees — Compensation — Employees’ Share Incentive Plan, or the 2007 Plan, the 2005 Employee’s Stock Option Plan, or the 2005 Plan, the 2003 Employee’s Option Plan, or the 2003 Plan, and the 2000 Employee’s Stock Option Plan, or the 2000 Plan.Plans.” As a result of thesethe grants and potential future grants under theseour share incentive plans, we had incurred in the past and expect to continue to incur in future periods significant share-based compensation expenses. The amount of these expenses is based on the fair value of the share-based awards.

Our board of directors has the discretion to change terms of any previously issued share options and any such change may significantly increase the amount of our share-based compensation expenses for the period that the change takes effect as well as those for any future periods. In February 2009, our board of directors approved to reduce the exercise price of all outstanding unvested options that were granted by us in 2007 and 2008 under our 2007 Plan to the then fair market value of our ordinary shares underlying such options and, in December 2009, our board of directors approved to extend the expiration dates of all stock options granted in 2005 and 2006 to eight years after the respective original grant dates of these options. As a result of such changes, our share-based compensation expense of 2009 reduced our diluted earnings per ADS by US$0.14. In February 2010, our compensation committee approved to extend the expiration dates of all stock options granted in and after 2007 to eight years after the respective original grant dates of these options. As a result of such changes and extensions, our share-based compensation expense of 2010 reduced our diluted earnings per ADS by US$0.06. In addition, with such changes and extensions, the application of ASC 718 will continue to have a significant impact on our net income. In addition,Further, future changes to various assumptions used to determine the fair value of awards issued or the amount and type of equity awards granted may also create uncertainty as to the amount of future share-based compensation expense.

Changes in accounting standards may affect the results of our operations.

We are required to adopt new accounting standards under FASB from time to time. Certain new accounting standards may impose significant different accounting treatments on certain line items on our consolidated financial statements, which could result in unexpected changes to our results of operation.

For example, in May 2014, the FASB issued a new accounting standard on the recognition of revenue generated from contracts with customers that was designed to create greater comparability for financial statement users across industries and jurisdictions. The core principle of this new standard is that an “entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.” We adopted this new standard, effective from January 1, 2018, and applied the full retrospective transition approach to all contracts, which means that the financial statements were retrospectively adjusted. Financial statements of 2018 will be reported under this new standard. We do not expect that the new standard will change the presentation of the majority of our revenues on a net basis. However, the timing of revenue recognition for certain revenue streams will change under this new standard. For example, revenue for accommodation reservation services, which is primarily recognized after end users having completed their stays under the current standard, will change to be recognized once the reservation made becomes non-cancellable.

In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities. This accounting standard retains the current accounting for classifying and measuring investments in debt securities and loans, but requires equity investments to be measured at a fair value with subsequent changes recognized in net income, except for those accounted for under the equity method or requiring consolidation. This guidance also changes the accounting for investments without a readily determinable fair value and those do not qualify for the practical expedient to estimate a fair value. A policy election can be made for these investments whereby investment will be carried at cost and adjusted in subsequent periods for any impairment or changes in observable prices of identical or similar investments. This revised guidance is effective from the fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We applied the new standard beginning on January 1, 2018 and recognize the changes in fair value for all equity investments measured at fair value through net income/(loss). For investments in equity securities that lack readily determinable fair values, we will elect to use the alternative measurement defined as cost, less impairments, adjusted by observable price changes. We anticipate that the adoption of ASU 2016-01 will increase the volatility of its other income/(expense), net, as a result of the remeasurement of its equity securities upon the occurrence of observable price changes and impairments.

For further details, see “Item 5.A. Operating and Financial Review and Prospects — Operating Results — Critical Accounting Policy.” As a result of changes in accounting standards, our results of operations may be adversely affected.

Failure to maintain effective internal control over financial reporting could result in errors in our published financial statements, which in turn could have a material adverse effect on the trading price of our ADSs.

We are subject to the reporting obligations under the U.S. securities laws. The U.S. Securities and Exchange Commission, or the SEC, asAs required under Section 404 of the Sarbanes-Oxley Act of 2002, the SEC has adopted rules requiring public companies to include a report of management on the effectiveness of such companies’ internal control over financial reporting in its annual report. In addition, an independent registered public accounting firm for a public company must issue an attestation report on the effectiveness of the company’s internal control over financial reporting. Our management conducted an evaluation of the effectiveness of our internal control over financial reporting and concluded that our internal control over financial reporting was effective as of December 31, 2015.2017. In addition, our independent registered public accounting firm attested the effectiveness of our internal control and reported that our internal control over financial reporting was effective as of December 31, 2015.2017. If we fail to maintain the effectiveness of our internal control over financial reporting, we may not be able to conclude on an ongoing basis that we have effective internal control over financial reporting in accordance with the Sarbanes-Oxley Act. Moreover, effective internal control over financial reporting is necessary for us to produce reliable financial reports. As a result, any failure to maintain effective internal control over financial reporting could result in the loss of investor confidence in the reliability of our financial statements, which in turn could negatively impact the trading price of our ADSs. Furthermore, we may need to incur additional costs and use additional management and other resources in an effort to comply with Section 404 of the Sarbanes-Oxley Act and other requirements going forward.

We may need additional capital and we may not be able to obtain it.

We believe that our current cash and cash equivalents, short-term investments, cash flow from operations and proceeds from our financing activities will be sufficient to meet our anticipated cash needs for the foreseeable future. We may, however, require additional cash resources due to changed business conditions or other future developments, including any investments or acquisitions we may decide to pursue. If these resources are insufficient to satisfy our cash requirements, we may seek to sell additional equity or debt securities or obtain a credit facility. The sale of additional equity securities could result in additional dilution to our shareholders. The incurrence of indebtedness would result in increased debt service obligations and could result in operating and financing covenants that would restrict our operations. We cannot assure you that financing will be available in amounts or on terms acceptable to us, if at all. In particular, the recent financial turmoil affecting the financial markets and banking system may significantly restrict our ability to obtain financing in the capital markets or from financial institutions on commercially reasonable terms, or at all.

Risks Related to Our Corporate Structure

PRC laws and regulations restrict foreign investment in the air-ticketing, travel agency and value-added telecommunications businesses, and substantial uncertainties exist with respect to the application and implementation of PRC laws and regulations.

We are a Cayman Islands incorporated company and a foreign person under PRC law. Due to foreign ownership restrictions in the air-ticketing, travel agency and value-added telecommunications industries, we conduct part of our business through contractual arrangements with our consolidated affiliated Chinese entities. These entities hold the licenses and approvals that are essential for our business operations.

In the opinion of our PRC counsel, Commerce & Finance Law Offices, our current ownership structure, the ownership structure of our subsidiaries and our consolidated affiliated Chinese entities, the contractual arrangements among us, our subsidiaries, our consolidated affiliated Chinese entities and their shareholders, as described in this annual report, are in compliance with existing PRC laws, rules and regulations. There are, however, substantial uncertainties regarding the interpretation and application of current or future PRC laws and regulations. Accordingly, we cannot assure you that PRC government authorities will not ultimately take a view contrary to the opinion of our PRC legal counsel due to the lack of official interpretation and clear guidance.

If we and our consolidated affiliated Chinese entities are found to be in violation of any existing or future PRC laws or regulations, the relevant governmental authorities would have broad discretion in dealing with such violation, including, without limitation, levying fines, confiscating our income or the income of our consolidated affiliated Chinese entities, revoking our business licenses or the business licenses of our consolidated affiliated Chinese entities, requiring us and our consolidated affiliated Chinese entities to restructure our ownership structure or operations and requiring us or our consolidated affiliated Chinese entities to discontinue any portion or all of our value-added telecommunications, air-ticketing or travel agency businesses. In particular, if the PRC government authorities impose penalties which cause us to lose our rights to direct the activities of and receive economic benefits from our consolidated affiliated Chinese entities, we may lose the ability to consolidate and reflect in our financial statements the operation results of our consolidated affiliated Chinese entities. Any of these actions could cause significant disruption to our business operations, and may materially and adversely affect our business, financial condition and results of operations.

According to the PRC Property Rights Law, effective as of October 1, 2007, and the Measures for the Registration of Equity Pledge with the PRC State Administration for Industry and Commerce (2016 Revision), effective as of April 29, 2016, the effectiveness of the pledges will be denied if the pledges are not registered with the PRC State Administration for Industry and Commerce, or SAIC. Our equity pledges have been duly registered with the relevant local branches of SAIC. Under the equity pledge agreements between our subsidiaries and the shareholders of our consolidated affiliated Chinese entities, the shareholders of our consolidated affiliated Chinese entities pledged their respective equity interests in these entities to our subsidiaries. According to the PRC Property Rights Law, effective as of October 1, 2007, and the Measures for the Registration of Equity Pledge with the Administration for Industry and Commerce, effective as of October 1, 2008, theThe effectiveness of the pledges will be denied if the pledges are not registered with the Administration for Industry and Commerce. Our consolidated affiliated Chinese entities and our subsidiaries have registered most of the equity pledges, except thatupon registration process for a few equity pledges was pending as of the date of this annual report. The effectiveness of the pledges will be recognized by PRC courts if disputes arise on certain pledged equity interests and that our subsidiaries’ interests as pledgees will prevail over those of third parties.

Furthermore, we were aware that a China-based U.S.-listed company listed in the U.S. announced in 2012 that it was subject to the SEC’s investigation, which it believed was related to the consolidation of its consolidated affiliated Chinese entities. Following the announcement, that issuer’s stock price declined significantly. Although we are not aware of any actual or threatened investigation, inquiry or other action by the SEC, NASDAQNasdaq or any other regulatory authority with respect to consolidation of our consolidated affiliated Chinese entities, we cannot assure you that we will not be subject to any such investigation or inquiry in the future. In the event we are subject to any regulatory investigation or inquiry relating to our consolidated affiliated Chinese entities, including the consolidation of such entities into our financial statements, or any other matters, we may need to spend significant amount of time and expenses in connection with the investigation or inquiry, our reputation may be harmed regardless of the outcome, and the trading price of our ADS may materially decline or fluctuate.

If our consolidated affiliated Chinese entities violate our contractual arrangements with them, our business could be disrupted, our reputation may be harmed and we may have to resort to litigation to enforce our rights, which may be time-consuming and expensive.

As the PRC government restricts foreign ownership of value-added telecommunications, air-ticketing and travel agency businesses in China, we depend on our consolidated affiliated Chinese entities, in which we have no ownership interest, to conduct part of our non-accommodation reservation business activities through a series of contractual arrangements, which are intended to provide us with effective control over these entities and allow us to obtain economic benefits from them. Although we have been advised by our PRC counsel, Commerce & Finance Law Offices, that the contractual arrangements as described in this annual report are valid, binding and enforceable under current PRC laws, except for certain equity pledge agreements whose registration process was pending as of the date of this annual report and thus may not be enforceable, these arrangements are not as effective in providing control as direct ownership of these businesses. For example, our consolidated affiliated Chinese entities could violate our contractual arrangements with them by, among other things, failing to operate our air-ticketing or packaged-tour business in an acceptable manner or pay us for our consulting or other services. In any such event, we would have to rely on the PRC legal system for the enforcement of those agreements, which could have uncertain results. Any legal proceeding could result in the disruption of our business, damage to our reputation, diversion of our resources and incurrence of substantial costs. See “—“Item 3.D. Key Information — Risk Factors — Risks Related to Doing Business in China — Uncertainties with respect to the PRC legal system could adversely affect us.”

The principal shareholders of our consolidated affiliated Chinese entities have potential conflictsconflict of interest with us, which may adversely affect our business.

Our director, vice chairmanSome of the boardour directors and president, Min Fan, our officers Tao Yang, Qi Shi, Maohua Sun, Hui Cao and Hui Wang were also the principal shareholders of our consolidated affiliated Chinese entities as of the date of this annual report. Thus, conflictsconflict of interest between their duties to our company and their interests in our consolidated affiliated Chinese entities may arise. We cannot assure you that when conflictsconflict of interest arise,arises, these persons will act entirely in our interests or that the conflictsconflict of interest will be resolved in our favor. In addition, these persons could violate their non-competition or employment agreements with us or their legal duties by diverting business opportunities from us to others, resulting in our loss of corporate opportunities. In any such event, we would have to rely on the PRC legal system for the enforcement of these agreements, which could have uncertain results. Any legal proceeding could result in the disruption of our business, diversion of our resources and incurrence of substantial costs. See “—“Item 3.D. Key Information — Risk Factors — Risks Related to Doing Business in China — Uncertainties with respect to the PRC legal system could adversely affect us.”

Substantial uncertainties exist with respect toOur business may be significantly affected by the enactment timetable, interpretation and implementation of draft PRCDraft Foreign Investment Law, and how it may impact the viability of our current corporate structure, corporate governance and business operations.if implemented as proposed.

The Ministry of Commerce, or MOC,On January 19, 2015, MOFCOM published a discussionthe draft Foreign Investment Law. At the same time, MOFCOM published an accompanying explanatory note of the proposeddraft Foreign Investment Law, in January 2015 aimingwhich contains important information about the draft Foreign Investment Law, including its drafting philosophy and principlesplans to upon its enactment, replacetransition to the trionew legal regime and treatment of existing laws regulating foreign investmentbusiness in China namely, the Sino-foreign Equity Joint Venture Enterprise Law, the Sino-foreign Cooperative Joint Venture Enterprise Law and the Wholly Foreign-invested Enterprise Law, together with their implementation rules and ancillary regulations.controlled by foreign invested enterprises. The draft Foreign Investment Law embodies an expectedproposed significant changes to the PRC regulatory trend to rationalize its foreign investment regulatorylegal regime and, when implemented, may have a significant impact on businesses in line with prevailing international practice and the legislative efforts to unify the corporate legal requirements for bothChina controlled by foreign and domestic investments. The MOCinvested enterprises primarily through contractual arrangements, such as our business. MOFCOM solicited comments on this draft and substantial uncertainties exist with respect to its enactment timetable, interpretation and implementation. The draft Foreign Investment Law, if enacted as proposed, may materially impact the entire legal framework regulating the foreign investments in China as well as the viability of our current corporate structure, corporate governance and business operations in many aspects.

Among other things, the draft Foreign Investment Law expands the definition of foreign investment and introduces the principle of “actual control” in determining whether a company is considered a foreign-invested enterprise, or an FIE. The2015, but no new draft Foreign Investment Law specifically provides that entities established in China but “controlled” by foreign investors will be treated as FIEs, whereas an entity set up in a foreign jurisdiction would nonetheless be, upon market entry clearance by the MOC, treated as a PRC domestic investor provided that the entity is “controlled” by PRC entities and/or citizens.  In this connection, “control” is broadly defined in the draft law to cover any of the following summarized categories: (i) holding 50% of or more of the equity interest, share of interests, voting rights or similar equity interest of the subject entity; (ii) holding less than 50% of the equity interest, share of interests, voting rights or similar equity interest of the subject entity but having the power to secure at least 50% of the seats on the board or other equivalent decision making bodies, or having the voting power to material influence on the board, the shareholders’ meeting or other equivalent decision making bodies; or (iii) having the power to exert decisive influence, via contractual or trust arrangements, over the subject entity’s operations, financial matters or other key aspects of business operations. Once an entity is determined to be an FIE and its investment amount exceeds certain thresholds or its business operation falls within a “negative list” to be separately issued by the State Counsel Council in the future, market entry clearance by the MOC or its local counterparts would be required. Otherwise, all foreign investors may make investments on the same terms as Chinese investors without being subject to additional approval from the government authorities as mandated by the existing foreign investment legal regime.

The “variable interest entity” structure, or VIE structure, has been adopted by many PRC-based companies, including us, to obtain necessary licenses and permits in the industries that are currently subject to foreign investment restrictions in China. See “Item 3. Key Information — D. Risk Factors — Risks Related to Our Corporate Structure — PRC laws and regulations restrict foreign investment in the air-ticketing, travel agency, advertising and value-added telecommunications businesses, andpublished since then. There is substantial uncertainties existuncertainty with respect to the applicationits final content, interpretation, adoption timeline and implementation of PRC laws and regulations.” and “Item 7. Major Shareholders and Related Party Transactions — Related Party Transactions — Arrangements with Consolidated Affiliated Chinese Entities.” Undereffective date. It is anticipated, however, that the draft Foreign Investment Law will reflect regulations on variable interest entities that are controlled via contractual arrangements would also be deemedentities. MOFCOM suggests both registration and approval as FIEs, ifpotential options for the regulation of variable interest entity structures, depending on whether they are ultimately “controlled”“Chinese” or “foreign controlled.” One of the core concepts of the draft Foreign Investment Law is “de facto control,” which emphasizes substance over form in determining whether an entity is “Chinese” or “foreign-controlled.” “Chinese investors” are individuals who are Chinese nationals, Chinese government agencies and any domestic enterprise controlled by Chinese nationals or government agencies. “Foreign investors” are foreign citizens, foreign governments, international organizations and entities controlled by foreign investors. Therefore, for any companies with a VIE structure in an industry category that is on the “negative list,” the existing VIE structure may be deemed legitimate only if the ultimate controlling person(s) is/are of PRC nationality (either PRC state owned enterprises or agencies, or PRC citizens). Conversely, if the actual controlling person(s) is/are of foreign nationalities, then the variable interest entities will be treated as FIEscitizens and any operation in the industry category on the “negative list” without market entry clearance may be considered as illegal.entities.

It is likely that we would not be considered as ultimately controlled by PRC nationals, as our shareholder base is relatively diverse and, to our knowledge, ultimate beneficial owners of our shares who are PRC nationals may not, in the aggregate, control more than 50% of our total voting power as of March 31, 2016.the date of this annual report. The draft Foreign Investment Law has not taken a position on what actions will be taken with respect to the existing companies with a VIE structure, whether or not these companies are controlled by ChinesePRC parties, while it solicited comments from the public on this point by illustrating several possible options. Under these varied options, a company that has a VIE structure and conducts the business on the “negative list” at the time of enactment of the new Foreign Investment Law has either the option or obligation to disclose its corporate structure to the authorities, while the authorities, after reviewing the ultimate share control structure of the company, may either permit the company to continue maintain the VIE structure (if the company is deemed ultimately controlled by PRC nationals), or require the company to dispose of its businesses and/or VIE structure based on circumstantial considerations. Moreover, it is uncertain whether the air-ticketing, travel agency and value-added telecommunications industries, in which our variable interest entities operate, will be subject to the foreign investment restrictions or prohibitions set forth in the “negative list” to be issued. If the enacted version of the Foreign Investment Law and the final “negative list” mandate further actions, such as MOCMOFCOM market entry clearance or certain restructuring of our corporate structure and operations, to be completed by companies with existing VIE structure like us, we face substantial uncertainties as to whether these actions can be timely completed, or at all, and our business and financial condition may be materially and adversely affected.

The draft Foreign Investment Law, if enacted as proposed, may also materially impact our corporate governance practice and increase our compliance costs. For instance, the draft Foreign Investment Law imposes stringent ad hoc and periodic information reporting requirements on foreign investors and the applicable FIEs. Aside from investment implementation report and investment amendment report that are required at each investment and alteration of investment specifics, an annual report is mandatory, and large foreign investors meeting certain criteria are required to report on a quarterly basis. Any company found to be non-compliant with these information reporting obligations may potentially be subject to fines and/or administrative or criminal liabilities, and the persons directly responsible may be subject to criminal liabilities.

Our contractual arrangements with our consolidated affiliated Chinese entities may result in adverse tax consequences to us.

As a result of our corporate structure and the contractual arrangements between us and our consolidated affiliated Chinese entities, we are effectively subject to the 5% PRC business tax or 6% PRC value-added taxestax, or VAT, on both revenues generated by our consolidated affiliated Chinese entities’ operations in China and revenues derived from our contractual arrangements with our consolidated affiliated Chinese entities. We maymight be subject to adverse tax consequences if the PRC tax authorities were to determine that the contracts between us and our consolidated affiliated Chinese entities were not made on an arm’s-length basis and therefore constitute favorable transfer pricing arrangements. If this occurs, the PRC tax authorities could request that our consolidated affiliated Chinese entities adjust their taxable income upward for PRC tax purposes. Such a pricingan adjustment could adversely affect us by increasing our consolidated affiliated Chinese entities’ tax expenses without reducing our tax expenses, which could subject our consolidated affiliated Chinese entities to late payment fees and other penalties for underpayment of taxes, and/or result in the loss of the tax benefits available to our subsidiaries in China. The EIT Law requires every enterprise in China to submit its annual enterprise income tax return together with a report on transactions with its affiliates to the relevant tax authorities. The tax authorities may impose reasonable adjustments on taxation if they have identified any related party transactions that are inconsistent with arm’s-length principles. As a result, our contractual arrangements with our consolidated affiliated Chinese entities may result in adverse tax consequences to us.

Our subsidiaries and consolidated affiliated Chinese entities in China are subject to restrictions on paying dividends or making other payments to us, which may restrict our ability to satisfy our liquidity requirements.

We are a holding company incorporated in the Cayman Islands. We rely on dividends from our subsidiaries in China and consulting and other fees paid to us by our consolidated affiliated Chinese entities. Current PRC regulations permit our subsidiaries to pay dividends to us only out of their accumulated profits, if any, determined in accordance with ChinesePRC accounting standards and regulations. In addition, our subsidiaries and consolidated affiliated Chinese entities in China are required to set aside at least 10% of their respective accumulated profits each year, if any, to fund certain reserve funds unless these reserves have reached 50% of the subsidiaries’subsidiaries and consolidated affiliated Chinese entities’ registered capital. These reserves are not distributable as cash dividends. Furthermore, if our subsidiaries and consolidated affiliated Chinese entities in China incur debt on their own behalf in the future, the instruments governing the debt may restrict their ability to pay dividends or make other payments to us, which may restrict our ability to satisfy our liquidity requirements.

Pursuant to the EIT Law, its implementing rules and a circular of Taxation on Several Preferential Policies on Enterprise Income Tax issued by the PRC Ministry of Finance, or MOF, and the SAT, in February 2008, the dividends declared out of the profits earned after January 1, 2008 by an FIE to its immediate offshore holding company outside China are subject to a 10% withholding tax unless such foreign investor’soffshore holding company’s jurisdiction of incorporation has a tax treaty with China that provides for a different withholding arrangement, and certain supplementary requirements and procedures stipulated by SAT for such tax treaty are met and observed. Our subsidiaries in China are considered FIEs and are directly or indirectly held by our subsidiarysubsidiaries in Hong Kong. According to the currently effective tax treaty between China and Hong Kong, dividends payable by an FIE in China to a company in Hong Kong whichthat directly holds at least 25% of the equity interests in the FIE will be subject to a withholding tax of 5%. In February 2009, the SAT issued a new notice, Notice No. 81. According toSAT Notice No. 81, in orderpursuant to enjoy the preferential treatment on dividend withholding tax rates,which an enterprise must be the “beneficial owner” of the relevant dividend income and no enterprise is entitledin order to enjoy the preferential treatment pursuant to anywithholding tax treaties ifrates on dividend. If, however, such enterprise otherwise qualifies for such preferential withholding tax rates through any transaction or arrangement, the majorwhose main purpose of which is to obtainqualify for such preferential withholding tax treatment. Therates, the enterprise nevertheless cannot enjoy the preferential withholding tax rates and the competent tax authority in charge has the rightpower to make adjustments toadjust the applicable withholding tax rates if it determines that any taxpayer has enjoyed preferential treatment under tax treaties as a result of such transaction or arrangement.so determines. In October 2009, the SAT issued another notice on this matter,SAT Notice No. 601 to provide guidance on the criteria for determining whether an enterprise qualifies as the “beneficial owner” of the PRC sourced income for the purpose of obtaining preferential treatment under tax treaties. Pursuant to SAT Notice No. 601, the PRC tax authorities will review and grantpreferential tax preferential treatment on a case-by-case basis and adoptunder the “substance over form” principle in the review.and grant such treatment on a case-by-case basis. SAT Notice No. 601 specifies that a beneficial owner should generally carry out substantial business activities and own and have control over the income, the assets or other rights generating the income. Therefore, an agent or a conduit company will not be regarded as a beneficial owner of such income. Since the two notices were issued, it has remainedIt remains unclear how the PRC tax authorities will implement themSAT Notice No. 81 and SAT Notice No. 601 in practice and to what extent they will affect the dividend withholding tax rates for dividends distributed by our PRC subsidiaries in China to our Hong Kong subsidiary.subsidiaries. If the relevant tax authority determines that our Hong Kong subsidiary is a conduit company and does not qualify as the “beneficial owner” of the dividend income it receives from our PRC subsidiaries, the higher 10% withholding tax rate will apply to such dividends.

Under the EIT Law, an enterprise established outside of China with its “de facto management body” within China is considered a PRC resident enterprise and will be subject to enterprise income tax at the rate of 25% on its worldwide income. The “de facto management body” is defined as the organizational body that effectively exercises overall management and control over production and business operations, personnel, finance and accounting, and properties of the enterprise. It remains unclear how the PRC tax authorities will interpret such a broad definition. If the PRC tax authorities determine that we should be classified as a PRC resident enterprise for PRC tax purposes, our global income will be subject to income tax at a uniform rate of 25%, which may have a material adverse effect on our financial condition and results of operations. Notwithstanding the foregoing provision, the EIT Law also provides that, if a PRC resident enterprise directly invests in another PRC resident enterprise, the dividends received by the investing PRC resident enterprise from the invested PRC resident enterprise are exempted from income tax, subject to certain conditions. However, it remains unclear how the PRC tax authorities will interpret the PRC tax resident treatment of an offshore company like us, havingwith indirect ownership interests in PRC resident enterprises through intermediary holding vehicles.companies.

Moreover, under the EIT Law, foreign ADS holders that are not PRCnon-PRC resident enterprises may be subject to a 10% withholding tax upon dividends payable by a ChinesePRC entity that is considered as a PRC resident enterprise and gains realized on the sale or other disposition of ADSs or ordinary shares, if such income is considered as income derived from within China. Any such tax would reduce the returns on your investment in our ADSs.

If we exercise the option to acquire equity ownership in our consolidated affiliated Chinese entities, such ownership transfer require approval from or filings with PRC governmental authorities and subject to taxation, which may result in substantial costs to us.

Pursuant to the relevant contractual arrangements, threeboth of our PRC subsidiaries, Ctrip Travel Information and Ctrip Travel Network and Wancheng (Shanghai) Travel Agency Co., Ltd., or Wancheng (or their respective designees), each has itshave their respective exclusive rightrights to purchase all or any part of the equity interests in the applicable consolidated affiliated Chinese entities of ours from the respective shareholders of these consolidated affiliated Chinese entities for a price that is the higher of (i) the registeredamount of capital ofcontribution to such consolidated affiliated Chinese entities, or the consideration paid in exchange for the equity interests in such consolidated affiliated entities, or (ii) another minimum price as permitted by the then applicable PRC laws. Such equity transfers may be subject to approvals from, or filings with, relevant PRC governmental authorities. In addition, the relevant equity transfer priceprices may be subject to review and adjustment for tax adjustmentdetermination by the relevant tax authorities. Moreover, the shareholders of our consolidated affiliated Chinese entities, under the circumstances of such equity transfers, will be subject to PRC individual income tax on the difference between the equity transfer priceprices and the then current registered capital of the relevant consolidated affiliated Chinese entities. The shareholders of such consolidated affiliated Chinese entities will pay, after deducting such taxes, the remaining amount to Ctrip Travel Information or Ctrip Travel Network, or Wancheng, as appropriate, under the applicable contractual arrangements. The amount to be received by Ctrip Travel Information and Ctrip Travel Network and Wancheng may also be subject to enterprise income tax. Any of the aforementioned tax amounts could be substantial. Similar risk is faced by Qunar Software.

We face uncertainty with respect to indirect transfer of equity interests in PRC resident enterprises by their non-PRC holding companies.

We face uncertainties regarding the reporting on and consequences of previous private equity financing transactions involving the transfer and exchange of shares in our company by non-residentnon-PRC resident investors. According to the Notice on Strengthening Administration of Enterprise Income Tax for Share Transfers by Non-PRC Resident Enterprises issued by the PRC State Administration of TaxationSAT on December 10, 2009, or SAT Circular 698, where a non-residentnon-PRC resident enterprise transfers the equity interests in a PRC resident enterprise indirectly through a disposition of equity interests in an overseasoffshore holding company (other than a purchase and sale of shares issued by a PRC resident enterprise in public securities market), or an Indirect Transfer, the non-residentnon-PRC resident enterprise, as the seller, may be subject to PRC enterprise income tax of up to 10% of the gains derived from the Indirect Transfer in certain circumstances.

On February 3, 2015, the SAT issued Announcement on Several Issues Concerning the Enterprise Income Tax on Indirect Property Transfers by Non-RPC Resident Enterprises, or SAT Notice No. 7, to supersede the existing tax rules in relation to the tax treatment of the Indirect Transfer, while the other provisions of SAT Circular 698 irrelevant to the Indirect Transfer remain in force. SAT Notice No. 7 introduces a new tax regime that is significantly different from that under a notice issued by SAT Circular 698. It extends the SAT’s tax jurisdiction to capture not only the Indirect Transfer as set forth under SAT Circular 698 but also transactions involving indirect transfer of (i) real properties in China and (ii) assets of an “establishment or place” situated in China, by a non-PRC resident enterprise through a disposition of equity interests in an overseasoffshore holding company. SAT Notice No. 7 also extends the interpretation with respect to the disposition of equity interests in an overseasoffshore holding company.company broadly. In addition, SAT Notice No. 7 further clarifies how to assess reasonable commercial purposes and introduces safe harbors applicable to internal group restructurings. However, it also brings challenges to both the foreignoffshore transferor and transferee as they are required to make self-assessment on whether an Indirect Transfer or similar transaction should be subject to PRC tax and whether they should file or withhold any tax payment accordingly. On October 17, 2017, the SAT issued a Notice Concerning Withholding Income Tax of Non-Resident Enterprise, or SAT Notice No. 37, which abolishes SAT Circular 698 and certain provision of SAT Notice 7. SAT Notice No. 37 further reduces the burden of withholding obligator, such as revocation of contract filing requirements and tax liquidation procedures, strengthens the cooperation of tax authorities in different places, and clarifies the calculation of tax payable and mechanism of foreign exchange.

There is uncertainty as to the application of SAT Circular 698Notice No. 7 and SAT Notice No. 7.37. In the event that non-PRC resident investors were involved in our private equity financing transactions and such transactions were determined by the competent tax authorities as lack of reasonable commercial purposes, we and our non-PRC resident investors may become at risk of being taxed under SAT Circular 698 and SAT Notice No. 7 and SAT Notice No. 37 and may be required to expend costly resources to comply with SAT Circular 698 and SAT Notice No. 7 and SAT Notice No. 37, or to establish a case to be tax exempt under SAT Circular 698Notice No. 7 and SAT Notice No. 7,37, which may cause us to incur additional costs and may have a negative impact on the value of your investment in us.

The PRC tax authorities have discretion under SAT Circular 698Notice No. 7 and SAT Notice No. 737 to make adjustments toadjust the taxable capital gains based on the difference between the fair value of the transferred equity interests and the investment cost. We may pursue acquisitions in the future that may involve complex corporate structures. If we are considereddeemed as a non-PRC resident enterprise under the EIT Law and if the PRC tax authorities make adjustments toadjust the taxable income of the transactions under SAT Circular 698Notice No. 7 and SAT Notice No. 7,37, our income tax expenses associated with such potential acquisitions will be increased,increase, which may have an adverse effect on our financial condition and results of operations.

Risks Related to Doing Business in China

Adverse changes in economic and political policies of the PRC government could have a material adverse effect on the overall economic growth of China, which could adversely affect our business.

The majority of our business operations are conducted in mainland China. Accordingly, our results of operations, financial condition and prospects are subject to a significant degree to economic, political and legal developments in China. China’sThe Chinese economy differs from the economies of most developed countries in many respects, including with respect to the amount of government involvement, level of development, growth rate, control of foreign exchange and allocation of resources. While the PRCChinese economy has experienced significant growth in the past decades, that growth may not continue, as evidenced by the slowing of the growth of the Chinese economy since 2012. Any adverse changes in economic conditions in China, in the policies of the ChinesePRC government or in the laws and regulations in China could have a material adverse effect on the overall economic growth of China. Such developments could adversely affect our business and operating results, lead to reduction in demand for our services and adversely affect our competitive position. The PRC government has implemented various measures to encourage economic development and guide the allocation of resources. Some of these measures benefit the overall PRCChinese economy, but may also have a negative effect on us. For example, our financial condition and results of operations may be adversely affected by government control over capital investments or changes in tax regulations that are applicable to us. In addition, future measures to control the pace of economic growth may cause a decrease in the level of economic activity in China, which in turn could adversely affect our results of operations and financial condition.

Inflation in China may disrupt our business and have an adverse effect on our financial condition and results of operations.

The Chinese economy has experienced rapid expansion together with rising rates of inflation. Inflation may erode disposable incomes and consumer spending, which may have an adverse effect on the Chinese economy and lead to a reduction in business and leisure travel as the travel industry is highly sensitive to business and personal discretionary spending levels. This in turn could adversely impact our business, financial condition and results of operations.

Future movements in exchange rates between the U.S. dollardollars and the RMBRenminbi may adversely affect the value of our ADSs.

The value of the Renminbi against the U.S. dollardollars and other currencies may fluctuate and is affected by, among other things, changes in China’s political and economic conditions. The conversion of the Renminbi into foreign currencies, including the U.S. dollar,dollars, has been based on rates set by the People’s Bank of China. The PRC government allowed the Renminbi to appreciate by more than 20% against the U.S. dollardollars between July 2005 and July 2008. Between July 2008 and June 2010, this appreciation halted and the exchange rate between the Renminbi and the U.S. dollardollars remained within a narrow band. As a consequence, the Renminbi fluctuated significantly during that period against other freely traded currencies, in tandem with the U.S. dollar.dollars. Since June 2010, the PRC governmentRenminbi has allowed the Renminbi to appreciate slowlyfluctuated against the U.S. dollar again.dollars, at times significantly and unpredictably. It is difficult to predict how market forces or PRC or U.S. government policy may impact the exchange rate between the Renminbi and the U.S. dollardollars in the future.

The majority of our revenues and costs are denominated in Renminbi, while a portion of our financial assets and our dividend payments are denominated in U.S. dollars. We have not used any forward contracts orand currency borrowings to help hedge our exposure to foreign currency risk. Any significant revaluation of the Renminbi or the U.S. dollardollars may adversely affect our cash flows, earnings and financial position, and the value of, and any dividends payable on, our ADSs. For example, an appreciation of the Renminbi against the U.S. dollardollars would make any new RMB-denominatedRenminbi-denominated investments or expenditures more costly to us, to the extent that we need to convert U.S. dollars into Renminbi for such purposes. An appreciation of the Renminbi against the U.S. dollardollars would also result in foreign currency translation losses for financial reporting purposes when we translate our U.S. dollar-denominated financial assets into Renminbi, our reporting currency. Conversely, if we decide to convert Renminbi into U.S. dollars for the purpose of making payments for dividends on our ordinary shares or ADSs or for other business purposes, appreciation of the U.S. dollardollars against the Renminbi would have a negative effect on the U.S. dollar amount available to us.

Restrictions on currency exchange may limit our ability to receive and use our revenues effectively.

Because the majority of our revenues are denominated in the form of Renminbi, any restrictions on currency exchange may limit our ability to use Renminbi-denominated revenues generated in Renminbi to fund our business activities outside China or to make dividend payments in U.S. dollars. The principal PRC regulation governing foreign currency exchange in China is the Regulations on Administration of Foreign Currency Administration Rules,Exchange, as amended, or the Rules.Forex Regulations. Under the Rules,Forex Regulations, Renminbi is freely convertible for trade- and service-related foreign exchange transactions, but not for direct investment, loan or investment in securities outside China unless the prior approval of the State Administration of Foreign Exchange, or SAFE, is obtained. Although the PRC government regulations now allow greater convertibility of Renminbi for current account transactions, significant restrictions still remain. For example, foreign exchange transactions under our subsidiaries’ capital account, including principal payments in respect of foreign currency-denominated obligations, remain subject to significant foreign exchange controls and the approval of SAFE. These limitations could affect our ability to obtain foreign exchange for capital expenditures. We cannot be certain that the PRC regulatory authorities will not impose more stringent restrictions on the convertibility of Renminbi, especially with respect to foreign exchange transactions.

PRC regulations relating to the establishment of offshore special purpose companiesvehicles by PRC residents and the grant of employee stock options by overseas-listed companies may subject our PRC resident shareholders to personal liability and limit our ability to inject capital into our PRC subsidiaries, limit our subsidiaries’ ability to distribute profits to us, or otherwise adversely affect us.

SAFE issued a public notice, or SAFE Circular 75, in October 2005 requiring PRC residents to register with the local SAFE branchbranches before establishing or controlling any company outside of China for the purpose of capital financing with assets or equity interests in any onshore enterprise located in China, referred to in the notice as a “special purpose company.vehicle.” On July 4, 2014, SAFE issued the SAFE’s Notice on Relevant Issues Concerning Foreign Exchange Administration for PRC Residents to Engage in Outbound Investment and Financing and Inbound Investment via Special Purpose Vehicles, or SAFE Circular 37, which has superseded SAFE Circular 75. Under SAFE Circular 75, SAFE Circular 37 and other relevant foreign exchange regulations, PRC residents who make, or have previously made, prior to the implementation of these foreign exchange regulations, direct or indirect investments in offshore companies will be required to register those investments. In addition, any PRC resident who is a direct or indirect shareholder of an offshore company is also required to file or update the registration with the local branchbranches of SAFE, with respect to that offshore company for any material change involving its round-trip investment, capital variation, such as an increase or decrease in capital, transfer or swap of shares, merger, division, long-term equity or debt investment or the creation of any security interest. If any PRC shareholder fails to make the required registration or update the previously filed registration, the PRC subsidiary of that offshore parent company may be prohibited from distributing their profits and the proceeds from any reduction in capital, share transfer or liquidation to their offshore parent company, and the offshore parent company may also be prohibited from injecting additional capital into its PRC subsidiary. Moreover, failure to comply with the various foreign exchange registration requirements described above could result in liability under PRC laws for evasion of applicable foreign exchange restrictions.

We have notified holders of our ordinary shares of our company who we know are PRC residents to register with the local SAFE branchbranches as required under the applicable foreign exchange regulations. The failure or inability of our shareholdersPRC resident in Chinashareholders to comply with the registration procedures set forth therein may subject them to fines and legal sanctions and may also limit our ability to contribute additional capital into our PRC subsidiaries, limit our PRC subsidiaries’ ability to distribute profits to our company or otherwise adversely affect our business.

On February 15, 2012, SAFE promulgated the Circular on Relevant Issues Concerning Foreign Exchange Administration for Domestic Individuals Participating in an Employees Share Incentive Plan of an Overseas-Listed Company (which is replacing(replacing the oldprior circular “Applicationin 2007, Application Procedure of Foreign Exchange Administration for Domestic Individuals Participating in an Employee Stock Holding Plan or Stock Option Plan of an Overseas-Listed Company”, of 2007)Company), or the new Share Incentive Rule.Rules. Under the new Share Incentive Rule,Rules, PRC resident individuals who participate in a share incentive plan of an overseas publicly listed company are required to register with SAFE and complete certain other procedures. All such participants need to retain a PRC agent through PRC subsidiarysubsidiaries to register with SAFE and handle foreign exchange matters such as opening accounts, transferring and settlement of the relevant proceeds. The new Share Incentive RuleRules further requires thatrequire an offshore agent should alsoto be designated to handle matters in connection with the exercise or sale of share options and sale of proceeds transferring for the participants of share incentive plan participants.plans. We and our PRC employees who have been granted stock options are subject to the Share Incentive Rule.Rules. If we or our PRC optionees fail to comply with these regulations, we or our PRC optionees may be subject to fines and legal sanctions.

Uncertainties with respect to the PRC legal system could adversely affect us.

We conduct our business primarily through our wholly ownedwholly-owned subsidiaries incorporated in China. Our subsidiaries are generally subject to laws and regulations applicable to foreign investment in China and, in particular, laws applicable to wholly foreign owned enterprises.foreign-owned enterprises, or WFOEs. In addition, we depend on several consolidated affiliated Chinese entities in China to honor their service agreements with us. Almost all of these agreements are governed by PRC law and disputes arising out of these agreements are expected to be decided by arbitration in China. The PRC legal system is based on written statutes. Prior court decisions may be cited for reference but have limited precedential value. Since 1979, PRC legislation and regulations have significantly enhanced the protections afforded to various forms of foreign investments in China. However, since the PRC legal system is still evolving, the interpretations of many laws, regulations and rules are not always uniform and enforcement of these laws, regulations and rules involve uncertainties, which may limit remedies available to us. In addition, any litigation in China may be protracted and result in substantial costs and diversion of resources and management attention. If we and our consolidated affiliated Chinese entities are found to be in violation of any existing or future PRC laws or regulations, or fail to obtain or maintain any of the required permits or approvals, the relevant PRC regulatory authorities would have broad discretion in dealing with such violations, including restructuring. See “Risks“Item 3.D. Key Information — Risk Factors — Risks Related to Our Corporate Structure — PRC laws and regulations restrict foreign investment in the air-ticketing, travel agency and value-added telecommunications businesses, and substantial uncertainties exist with respect to the application and implementation of PRC laws and regulations.” and “Risks“Item 3.D. Key Information — Risk Factors — Risks Related to Our Corporate Structure — Substantial uncertainties exist with respect to the enactment timetable, interpretation and implementation of draft PRC Foreign Investment Law and how it may impact the viability of our current corporate structure, corporate governance and business operations.”

Implementation of laws and regulations relating to data privacy in China could adversely affect our business.

Certain data and services collected, provided or used by us or provided to and used by us or our users are currently subject to regulationregulations in certain jurisdictions, including China. The PRC Constitution states that PRC laws protect the freedom and privacy of communications of citizens and prohibit infringement of such basic rights, and the PRC Contract Law prohibits contracting parties from disclosing or misusing the trade secrets of the other party. Further, companies or their employees who illegally trade or disclose customer data may face criminal charges. Although the definition and scope of “privacy” and “trade secret” remain relatively ambiguous under PRC law, growing concerns about individual privacy and the collection, distribution and use of information about individuals have led to national and local regulations that could increase our expenses.

In December 2012, the Standing Committee of the National People’s CongressNPC enacted the Decision to Enhance the Protection of Network Information, or the Information Protection Decision, to further enhance the protection of users’ personal information in electronic form. The Information Protection Decision provides that Internet information servicesservice providers must expressly inform their users of the purpose, manner and scope of the collection and use of users’ personal information by Internet information servicesservice providers, publish the Internet information services providersservice providers’ standards for their collection and use of users’ personal information, and collect and use users’ personal information only with the consent of the users and only within the scope of such consent. The Information Protection Decision also mandates that Internet information servicesservice providers and their employees keep users’ personal information that they collect strictly confidential, and that they must take such technical and other measures as are necessary to safeguard the information against disclosure, damages and loss. Pursuant to the Order for the Protection of Telecommunication and Internet User Personal Information issued in July 2013 by China’sthe PRC Ministry of Industry and Information Technology (formerly known as the Ministry of Information Industry), or the MIIT, in July 2013, any collection and use of userusers’ personal information must be subject to the consent of the user,users, abide by the principles of legality, rationality and necessity and be within the specified purposes, methods and scopes. Compliance with current regulations and regulations that may come into effect in these areas may increase our expenses related to regulatory compliance, which could have an adverse effect on our financial condition and operating results.

PRC regulation of loans and direct investment by offshore holding companies to PRC entities may delay or prevent us from using the proceeds from the offerings of any securities to make loans or additional capital contributions to our PRC operating subsidiaries.

In September 2012, we completed an offering of US$180 million in aggregate principal amount of convertible senior notes due 2017.2017, or the 2017 Notes. In October 2013, we completed another offering of US$800 million in aggregate principal amount of 1.25% convertible senior notes due 2018. In August 2014, in May 2015 and in December 2015, we issued US$500 million in aggregate principal amount of convertible notes due 2019, US$250 million in aggregate principal amount of convertible notes due 2020 and US$500 million in aggregate principal amount of convertible notes due 2025, respectively, to Priceline Group Treasury Company B.V., an indirect wholly owned subsidiary of The Priceline Group Inc,2018, or Priceline Group.the 2018 Notes. In June 2015, we completed an offering of US$700 million in aggregate principal amount of 1.00% convertible senior notes due 2020, or the 2020 Notes, and US$400 million in aggregate principal amount of 1.99% convertible senior notes due 2025.2025, or the 2025 Notes. In September 2016, we concurrently completed an offering of 32,775,000 ADSs at US$45.96 per ADS (taking into account of the fully exercised over-allotment option) and an offering of US$975 million in aggregate principal amount of 1.25% convertible senior notes due 2022 (taking into account of the fully exercised over-allotment option), or the 2022 Notes. In August 2014, May 2015, December 2015 and September 2016, we issued US$500 million in aggregate principal amount of 1.00% convertible notes due 2019, or the 2019 Priceline Notes, US$250 million in aggregate principal amount of 1.00% convertible notes due 2020, or the 2020 Priceline Notes, US$500 million in aggregate principal amount of 2.00% convertible notes due 2025, or the 2025 Priceline Notes, and US$25 million in aggregate principal amount of 1.25% convertible notes due 2022, or the 2022 Priceline Notes, respectively, to Priceline Group Treasury Company B.V., an indirect wholly-owned subsidiary of The Priceline Group Inc., or Priceline. In December 2015, we issued US$500 million in aggregate principal amount of 2.00% convertible notes due 2025, or the 2025 Hillhouse Notes, to Gaoling Fund, L.P. and YHG Investment, L.P., or collectively Hillhouse, in addition to the aforementioned issuance to Priceline. In September 2016, we closed private placements of our ordinary shares with the respective subsidiaries of Baidu and Priceline Group.at an aggregate amount of US$100 million and US$25 million, respectively. As an offshore holding company, our ability to make loans or additional capital contributions to our PRC operating subsidiaries is subject to PRC regulations and approvals and there are restrictions for us to make loans to our consolidated affiliated Chinese entities. These regulations and approvals may delay or prevent us from using the proceeds we received in the past or will receive in the future from the offerings of securities to make loans or additional capital contributions to our PRC operating subsidiaries and our consolidated affiliated Chinese entities, and impair our ability to fund and expand our business which may adversely affect our business, financial condition and result of operations.

For example, on March 3, 2015, the SAFE promulgated a Circular on the Reforming of Administrative Methods Regarding the Foreign Exchange Capital Settlement of Foreign-Invested Companies, or SAFE Circular 19, which became effective on June 1, 2015 and replaced SAFE Circular 142. Originally,Previously, pursuant to SAFE Circular 142, the registered capital of a foreign-invested companyan FIE settled in RMBRenminbi converted from foreign currencies may only be used within the business scope approved by the applicable governmentalgovernment authority and may not be used for equity investments in China, and the PRC and foreign-invested companiesFIE may not change how they useit uses such capital without SAFE’s approval, and may not in any case use such capital to repay RMBRenminbi loans if they have not used the proceeds of such loans. Although SAFE Circular 19 restates certain restrictions on the use of investment capital denominated in foreign currency by foreign invested companies,FIEs, it specifies that the registered capital of a foreign-invested company,an FIE, denominated in foreign currency, can be converted into RMBRenminbi at the discretion of such foreign- invested companyFIE and can be used for equity investment in the PRCChina subject to the invested company’s filing of a reinvestment registration with the relevant local SAFE. On June 9, 2016, SAFE issued the Circular on Reforming and Regulating the Administrative Policy of the Settlement under Capital Accounts, or SAFE Circular 16, which became effective on the same date. Although SAFE Circular 16 further extends the reform to cover foreign currency income under capital account, including capital, foreign debt and proceeds from offshore offering and listing, an FIE’s foreign currency income and such income settled in Renminbi under the capital account cannot be used directly and indirectly for any purposes out of the FIE’s business scope or in areas prohibited by laws and regulations. However, since Circular 19 is newly issued, itsthe interpretation and enforcement involve significantof SAFE Circular 19 and SAFE Circular 16 remained to be subject to uncertainty.

In light of the various requirements imposed by PRC regulations on loans to and direct investment in PRC entities by offshore holding companies, including Circular 19, we cannot assure you that we will be able to complete the necessary government registrations or obtain the necessary government approvals on a timely basis, if at all, with respect to future loans by us to our PRC subsidiarysubsidiaries or with respect to future capital contributions by us to our PRC subsidiary.subsidiaries. If we fail to complete such registrations or obtain such approvals, our ability to use the proceeds we received from our initial public offeringvarious offerings and to capitalize or otherwise fund our PRC operations may be negatively affected, which could materially and adversely affect our liquidity and our ability to fund and expand our business.

We have attempted to comply with the PRC government regulations regarding licensing requirements by entering into a series of agreements with our consolidated affiliated Chinese entities. If the PRC laws and regulations change, our business in China may be adversely affected.

To comply with the PRC government regulations regarding licensing requirements, we have entered into a series of agreements with our consolidated affiliated Chinese entities to exertmaintain our operational control over them and secure consulting fees and other payments from them. Although we have been advised by our PRC counsel, Commerce & Finance Law Offices, that our contractual arrangements with our consolidated affiliated Chinese entities, as described in this annual report, are valid under current PRC lawlaws and regulations, as there is substantial uncertainty regarding the interpretation and application of PRC laws and regulations, we cannot assure you that the PRC government would agree with our counsels’counsel’s position or that we will not be required to restructure our organizational structure and operations in China to comply with changing and new PRC laws and regulations. Restructuring of our operations may result in disruption of our business, diversion of management attention and the incurrence of substantial costs. See “Risks“Item 3.D. Key Information — Risk Factors — Risks Related to Our Corporate Structure — Substantial uncertainties exist with respect to the enactment timetable, interpretation and implementation of draft PRC Foreign Investment Law and how it may impact the viability of our current corporate structure, corporate governance and business operations.”

The continued growth of the Chinese Internet market depends on the establishment of an adequate telecommunications infrastructure.

Although private sector Internet service providers currently exist in China, almost all access to the Internet is maintained through state-owned telecommunication operations under theMIIT’s administrative control and regulatory supervision of the MIIT.supervision. In addition, the national networks in China connect to the Internet through government-controlled international gateways. These international gateways are the only channels through which a domestic ChinesePRC user can connect to the international Internet network. We rely on this infrastructure, primarily China Telecom and China Unicom, to provide data communications capacity. Although the PRC government has announced plans to aggressively develop the national information infrastructure, we cannot assure you that this infrastructure will be developed. In addition, we will have no access to alternative networks and services, on a timely basis if at all, in the event of any infrastructure disruption or failure. The Internet infrastructure in China may not support the demands associated with continued growth in Internet usage.

In addition, we have no control over the costs of the services provided by telecommunication service providers. If the prices we pay for telecommunications and internetInternet services rise significantly, our results of operations may be materially and adversely affected. Furthermore, if internetInternet access fees or other charges to internetInternet users increase, some users may be prevented from accessing the mobile internetInternet and thus cause the growth of mobile internetInternet users to decelerate. Such deceleration may adversely affect our ability to continue to expand our user base and maintain our user experience.

Our auditor, like other independent registered public accounting firms operating in China, is not permitted to be subject to inspection by Public Company Accounting Oversight Board, and as such, investors may be deprived of the benefits of such inspection.

Our independent registered public accounting firm that issues the audit reports included in our annual reports filed with the SEC, as an auditor of companies that are traded publicly in the United States and a firm registered with the Public Company Accounting Oversight Board (United States), or PCAOB, is required by the laws of the United States to undergo regular inspections by PCAOB to assess its compliance with the applicable professional standards. Because our auditor is located in China, a jurisdiction where PCAOB is currently unable to conduct inspections without the approval of the PRC authorities, our auditor, like other independent registered public accounting firms operating in China, is currently not inspected by PCAOB.

Inspections of other firms that PCAOB has conducted outside of China have identified deficiencies in those firms’ audit procedures and quality control procedures, which may be addressed as part of the inspection process to improve future audit quality. The inability of PCAOB to conduct inspections of independent registered public accounting firms operating in China makes it more difficult to regularly evaluate the effectiveness of our auditor’s audit procedures or quality control procedures. As a result, investors may be deprived of the benefits of PCAOB inspections.

Proceedings instituted by the SEC against the Big Four PRC-based accounting firms, including our independent registered public accounting firm, could result in our financial statements being determined to not be in compliance with the requirements of the Securities Exchange Act.Act of 1934, as amended.

In December 2012, the SEC brought administrative proceedings against the Big Four accounting firms, including our independent registered public accounting firm in China, alleging that they had refused to produce audit work papers and other documents related to certain other China-based companies under SEC’s investigation by the SEC for potential accounting fraud. On January 22, 2014, an initial administrative law decision, or Initial Decision, was issued, censuring these accounting firms and suspending four of the five firms from practicing before the SEC for a period of six months. The accounting firms filed a Petition for Review of the Initial Decision to the SEC. On February 6, 2015, the Big Four China-based accounting firms each agreed to a censure and to pay a fine to the SEC to settle the dispute and avoid suspension of their ability to practice before the SEC and audit U.S.-listed companies. The settlement required the firms to follow detailed procedures and to seek to provide the SEC with access to ChinesePRC firms’ audit documents via the China Securities Regulatory Commission, or the CSRC. If future document productions fail to meet specified criteria, the SEC retains authority to impose a variety of additional remedial measures on the firms depending on the nature of the failure. While we cannot predict if the SEC will further review the four China-based accounting firms’ compliance with specified criteria or if the results of such a review would result in the SEC imposing penalties such as suspensions or restarting the administrative proceedings, if the accounting firms are subject to additional remedial measures, our ability to file our financial statements in compliance with SEC requirements could be impacted. A determination that we have not timely filed financial statements in compliance with SEC requirements could ultimately lead to the delisting of our common stockADSs from NASDAQNasdaq or the termination of the registration of our common stockADSs under the Securities Exchange Act of 1934, as amended, or the Exchange Act, or both, which would substantially reduce or effectively terminate the trading of our common stockADSs in the United States.

Risks Related to Our Ordinary Shares and ADSs

The future sales of a substantial number of ADSs in the public market could adversely affect the price of the ADSs.

In the future, we may sell additional ADSs to raise capital, and our existing shareholders could sell substantial amounts of the ADSs, including those issued upon the exercise of outstanding options, in the public market. We cannot predict the size of such future issuance or the effect, if any, that they may have on the market price of the ADSs. Any future sales of a substantial number of the ADSs in the public market, or the perception that such issuance and sale may occur, could adversely affect the price of the ADSs and impair our ability to raise capital through the sale of additional equity securities.

Provisions of our convertible notes could discourage an acquisition of us by a third party.

In September 2012, we completed an offeringAs of US$180 million inDecember 31, 2017, the aggregate principal amount of convertible senior notes due 2017. In October 2013, we completed another offering of US$800 million in aggregate principal amount of convertible senior notes due 2018. In August 2014, in May 2015 and December 2015, we issued US$500 million in aggregate principal amount ofour outstanding convertible notes due 2019,was US$250 million in aggregate principal amount of convertible notes due 2020 and US$500 million in aggregate principal amount of convertible notes due 2025, respectively to Priceline Group Treasury Company B.V., an indirect wholly owned subsidiary of Priceline Group. In June 2015, we completed an offering of US$700 million in aggregate principal amount of convertible senior notes due 2020 and US$400 million in aggregate principal amount of convertible senior notes due 2025. In December 2015, we issued US$500 million in aggregate principal amount of convertible notes due 2025 to Hillhouse, in addition to the aforementioned issuance to Priceline Group.4.3 billion. Certain provisions of our convertible notes could make it more difficult or more expensive for a third party to acquire us. The indentures for these convertible notes define a “fundamental change” to include, among other things: (1) any person or group gaining control of our company; (2) our company merging with or into another company or disposing of substantially all of its assets; (3) any recapitalization, reclassification or change of our ordinary shares or the ADSs as a result of which these securities would be converted into, or exchanged for, stock, other securities, other property or assets; (4) the adoption of any plan relating to the dissolution or liquidation of our company; or (5) our ADSs ceasing to be listed on a major U.S. national securities exchange.exchange in certain circumstances, subject to certain exceptions where the applicable consideration comprises U.S.-listed common equity or ADSs. Upon the occurrence of a fundamental change, holders of these notes will have the right, at their option, to require us to repurchase all of their notes or any portion of the principal amount of such notes in integral multiples of US$1,000. In the event of a fundamental change, we may also be required to issue additional ADSs upon conversion of our convertible notes.

As a company incorporated in the Cayman Islands, we are permitted to adopt certain home country practices in relation to corporate governance matters that differ significantly from the NASDAQNasdaq corporate governance listing standards; these practices may afford less protection to shareholders than they would enjoy if we complied fully with the NASDAQNasdaq corporate governance listing standards.

As a Cayman Islands company listed on the NASDAQ,Nasdaq, we are subject to the NASDAQNasdaq corporate governance listing standards. However, NASDAQNasdaq rules permit a foreign private issuer like us to follow the corporate governance practices of its home country. Certain corporate governance practices in the Cayman Islands, which is our home country, may differ significantly from the NASDAQNasdaq corporate governance listing standards. As we chosehave chosen, or may from time to time to choose, to follow home country practice exemptions with respect to certain corporate matters such as the requirement of majority independent directors on our board of directors, our shareholders may be afforded less protection than they otherwise would under the NASDAQNasdaq corporate governance listing standards applicable to U.S. domestic issuers. See “Item 16G. Corporate Governance.”

You may face difficulties in protecting your interests, and our ability to protect our rights through the U.S. federal courts may be limited, because we are incorporated under Cayman Islands law.

Our corporate affairs are governed by our memorandum and articles of association and by the Companies Law (2013(2016 Revision) of the Cayman Islands, or the Companies Law, and the common law of the Cayman Islands. The rights of our shareholders and the fiduciary duties of our directors under Cayman Islands law are not as clearly established as they would be under statutes or judicial precedents in some jurisdictions in the United States. In particular, the Cayman Islands has a less developed body of securities laws as compared to the United States. Therefore, our public shareholders may have more difficulties in protecting their interests in the face of actions by our management, directors or controlling shareholders than would shareholders of a corporation incorporated in a jurisdiction in the United States.

Your ability to bring an action against us or against our directors and officers, or to enforce a judgment against us or them, may be limited because we are incorporated in the Cayman Islands, and because we conduct the majority of our operations in China and because the majority of our directors and officers reside outside of the United States.

We are incorporated in the Cayman Islands, and we conduct the majority of our operations in China through our wholly ownedwholly-owned subsidiaries and several consolidated affiliated Chinese entities in China. Most of our directors and officers reside outside of the United States and most of the assets of those persons are located outside of the United States. As a result, it may be difficult for you to bring an action in the United States upon these persons. It may also be difficult for you to enforce in United States courts judgments obtained in United States courts based on the civil liability provisions of the United States federal securities laws against us and our officers and directors, most of whom are not residents in the United States and the substantial majority of whose assets are located outside of the United States. Even if you are successful in bringing an action of this kind, the laws of the Cayman Islands or China may render you unable to enforce a judgment against our assets or the assets of our directors and officers.

YouThe voting rights of holders of ADSs are limited by the terms of the deposit agreement, and you may not be able to exercise your right to vote.direct how the ordinary shares represented by your ADSs are voted.

As a holder of ADSs, you may instructwill not have any right to attend general meetings of our shareholders or to cast any votes directly at such meetings. You will only be able to exercise the voting rights that attach to the underlying ordinary shares represented by your ADSs indirectly by giving voting instructions to the depositary forin accordance with the ADSsprovisions of the deposit agreement. Under the deposit agreement, you may vote only by giving voting instructions to the depositary, as the registered holder of the underlying ordinary shares which are represented by your ADSs. Upon receipt of your voting instructions, the depositary will endeavor to vote the underlying ordinary shares underlyingin accordance with your ADSs. Otherwise, youinstructions. You will not be able to directly exercise yourany right to vote with respect to the underlying shares unless you withdraw the ordinary shares. However,shares and become the registered holder of such shares prior to the record date for the general meeting. Under our memorandum and articles of association, the minimum notice period required to be given by our company to our registered shareholders for convening a general meeting is seven days. When a general meeting is convened, you may not know about the meeting enough inreceive sufficient advance notice to enable you to withdraw the ordinary shares. If we askunderlying shares represented by your ADSs and become the registered holder of such shares prior to the record date for the general meeting to allow you to attend the general meeting and to vote directly with respect to any specific matter or resolution that is to be considered and voted upon at the general meeting. In addition, under our memorandum and articles of association, for the purposes of determining those shareholders who are entitled to attend and vote at any general meeting, our directors may close our register of members and/or fix in advance a record date for such meeting, and such closure of our register of members or the setting of such a record date may prevent you from withdrawing the underlying shares which are represented by your instructions,ADSs and becoming the registered holder of such shares prior to the record date, so that you would not be able to attend the general meeting or to vote directly. Where any matter is to be put to a vote at a general meeting, the depositary will endeavor to notify you of the upcoming vote and arrange to deliver our voting materials to you. We cannot assure you that you will receive the voting materials in time to ensure that you can instruct the depositary to vote the underlying shares that are represented by your shares.ADSs. In addition, the depositary and its agents are not responsible for failing to carry out voting instructions or for the manner of carrying out voting instructions. This means that you may not be able to exercise your right to votedirect the voting of the underlying shares that are represented by your ADSs and there may be nothing you can do if the shares underlying your ADSs are not voted as you requested.

Under our deposit agreement, the depositary will give us a discretionary proxy to vote the ordinary shares underlying your ADSs at shareholders’ meetings if you do not vote, unless we have instructed the depositary that we do not wish a discretionary proxy to be given or any of the other situations specified under the deposit agreement takes place. The effect of this discretionary proxy is that you cannot prevent ordinary shares underlying your ADSs from being voted, absent the situations described above, and it may make it more difficult for shareholders to influence the management of our company. Holders of our ordinary shares are not subject to this discretionary proxy.

Your right to participate in any future rights offerings may be limited, which may cause dilution to your holdings.

We may from time to time distribute rights to our shareholders, including rights to acquire our securities. However, we cannot make rights available to you in the United States unless we register the rights and the securities to which the rights relate under the Securities Act of 1933, as amended, or the Securities Act, or an exemption from the registration requirements is available. Also, under the deposit agreement, the depositary bank will not make these rights available to you unless the distribution to ADS holders of both the rights and any related securities are either registered under the Securities Act, or exempt from registration under the Securities Act. We are under no obligation to file a registration statement with respect to any such rights or securities or to endeavor to cause such a registration statement to be declared effective. Moreover, we may not be able to establish an exemption from registration under the Securities Act. Accordingly, you may be unable to participate in our rights offerings and may experience dilution in your holdings.

You may not receive distributions on ordinary shares or any value for them if it is illegal or impractical to make them available to you.

The depositary has agreed to pay to you the cash dividends or other distributions it or the custodian receives on ordinary shares or other deposited securities after deducting its fees and expenses. You will receive these distributions in proportion to the number of ordinary shares your ADSs represent. However, the depositary is not responsible if it decides that it is unlawful or impractical to make a distribution available to any holders of ADSs. We have no obligation to register ADSs, ordinary shares, rights or other securities under U.S. securities laws. We also have no obligation to take any other action to permit the distribution of ADSs, ordinary shares, rights or anything else to holders of ADSs. This means that you may not receive the distribution we make on our ordinary shares or any value for them if it is illegal or impractical for us to make them available to you. These restrictions may have a material adverse effect on the value of your ADSs.

You may be subject to limitations on transfer of your ADSs.

Your ADSs are transferable on the books of the depositary. However, the depositary may close its transfer books at any time or from time to time when it deems expedient in connection with the performance of its duties. In addition, the depositary may refuse to deliver, transfer or register transfers of ADSs generally when our books or the books of the depositary are closed, or at any time if we or the depositary thinks it advisable to do so because of any requirement of law or of any government or governmental body, or under any provision of the deposit agreement, or for any other reason.

Provisions of our shareholder rights plan could delay or prevent an acquisition of our company, even if the acquisition would be beneficial to our shareholders.

In November 2007, we adopted a shareholder rights plan,, which was subsequently amended. Although the rights plan will not prevent a takeover, it is intended to encourage anyone seeking to acquire our company to negotiate with our board of directors prior to attempting a takeover by potentially significantly diluting an acquirer’s ownership interest in our outstanding shares. The existence of the rights plan may also discourage transactions that otherwise could involve payment of a premium over prevailing market prices for the ADSs.

We may be classified as a passive foreign investment company, which could result in adverse United States federal income tax consequences for U.S. Holders.United States investors in the ADSs or ordinary shares.

Based on the market price of ourthe ADSs and our ordinary shares, the value of our assets, and the composition of our assets and income,, we do not believe that we were a passive foreign investment company, or PFIC, for United States federal income tax purposes for our taxable year ended December 31, 2015. Given variance in the market price of our ADSs and ordinary shares, the value of our assets, and the composition of our assets and income, although we cannot be certain, we believe there is some risk that we will be treated as a PFIC for our taxable year ending December 31, 2016. Nevertheless, the2017. The application of the PFIC rules is subject to ambiguity in several respects and, in addition, we must make annuala separate determination each year as to whether we are a PFIC (afterafter the close of each taxable year).year. Accordingly, we cannot assure you of our PFIC status for our current taxable year ending December 31, 20162018 or for any future taxable year.

A non-U.S. corporation will be considered a PFIC for any taxable year if either (i) at least 75% of its gross income is passive income or (ii) at least 50% of the value of its assets (based on an average of the quarterly values of the assets during a taxable year) is attributable to assets that produce, or are held for the production of, passive income. The value of our assets generally will be determined by reference to the market price of the ADSs and ordinary shares, which may fluctuate considerably. If we were treated as a PFIC for any taxable year during which a U.S. Holder (as defined in Item 10.E. Additional Information — Taxation — United States Federal Income Tax Considerations) held an ADS or an ordinary share, certain adverse United States federal income tax consequences could apply to the U.S. Holder (as defined herein).Holder. For a more detailed discussion of United States federal income tax consequences to U.S. Holders that would result from our classification as a PFIC, see “Item 10.10.E. Additional Information — Taxation — Certain United States Federal Income Tax Considerations — Passive Foreign Investment Company Rules.Considerations.”

ITEM 4.                        INFORMATION ON THE COMPANY

A.History and Development of the Company

We commenced our business in June 1999. In March 2000, we established a new holding company, Ctrip.com International, Ltd., in the Cayman Islands as an exempted company with limited liability under the Companies Law ofin the Cayman Islands.Islands, Ctrip.com International, Ltd., as our new holding company. Since our inception, we have conducted the majority of our operations in China and expanded our operations overseas in 2009. As of December 31, 2015,2017, we mainly operated our business through the following significant subsidiaries:

·                  C-Travel International Limited;

·                  Ctrip.com (Hong Kong) Limited;

·                  Ctrip Computer Technology (Shanghai) Co., Ltd., or Ctrip Computer Technology;

·                  Ctrip Travel Information Technology (Shanghai) Co., Ltd., or Ctrip Travel Information;

·                  Ctrip Travel Network Technology (Shanghai) Co., Ltd., or Ctrip Travel Network;

·                  Ctrip Information Technology (Nantong)Wancheng (Shanghai) Travel Agency Co., Ltd., or Ctrip Information Technology;Wancheng;

·                  Shanghai Hecheng International Travel Agency Co., Ltd., or Hecheng;

·                  Beijing JointWisdomCtrip International Travel Agency Co., Ltd., or Beijing Ctrip;

·                  Shanghai Ctrip International Travel Agency Co., Ltd. (formerly known as Shanghai Ctrip Charming International Travel Agency Co., Ltd.), or Shanghai Ctrip;

·                  Chengdu Ctrip International Travel Agency Co., Ltd., or Chengdu Ctrip International;

·                  Chengdu Information Technology Co., Ltd., or JointWisdom (formerly known as China Software Hotel Information System Co., Ltd.);

·                  ezTravel Co., Ltd., or ezTravel; and

·                  HKWOT (BVI) Limited, or Wing On Travel.Chengdu Information;

After our share exchange transaction with Baidu in October 2015, we obtained approximately 45% of the aggregate voting interest of Qunar. In December 2015, we issued ordinary shares represented by ADSs to certain special purpose vehicles holding shares solely for the benefit of certain Qunar employees and, as consideration, we received class B ordinary shares of Qunar and directly injected these shares to a third-party investment entitiesentity dedicated to investing in business in China. From accounting perspective, we started to consolidate Qunar’s financial statements from December 31, 2015. Therefore, Qunar Cayman Islands Limited, the Cayman Islands holding company of Qunar, and its wholly-owned subsidiary, Beijing Qunar Software Technology Co., Ltd., or Qunar Software, may also be deemed as our significant subsidiaries from accounting perspective, although Qunar continues to operate its businesses independently.

We also conduct part of our business in China primarily through the following significant consolidated affiliated Chinese entities and certain of their subsidiaries:

·                  Shanghai Ctrip Commerce Co., Ltd., or Ctrip Commerce, which holds a value-added telecommunications business license;

·                  Beijing Ctrip International Travel Agency Co., Ltd., or Beijing Ctrip, which holds an air transport sales agency license, domestic and cross-border travel agency license;

·                  Guangzhou Ctrip Travel Agency Co., Ltd., or Guangzhou Ctrip, which holds an air transport sales agency license, domestic and cross-border travel agency license;

·                  Shanghai Ctrip International Travel Agency Co., Ltd., or Shanghai Ctrip, formerly known as Shanghai Ctrip Charming International Travel Agency Co., Ltd., which holds domestic and cross-border travel agency and air transport sales agency licenses;

·                  Shenzhen Ctrip Travel Agency Co., Ltd., or Shenzhen Ctrip, which holds an air transport sales agency license, domestic travel agency license;

·                  Chengdu Ctrip Travel Agency Co., Ltd, or Chengdu Ctrip, which holds an air transport sales agency license and a domestic travel agency license;

·                  Ctrip Insurance Agency Co., Ltd., or Ctrip Insurance, which holds an insurance agency business license;

·                  Shanghai Huacheng Southwest International Travel Agency Co., Ltd. (formerly known as Shanghai Huacheng Southwest Travel Agency Co., Ltd.), or Shanghai Huacheng, which holds domestic travel agency and air transport sales agency licenses;licenses.

·                  Chengdu Ctrip International Travel Agency Co., Ltd, or Chengdu Ctrip International, a wholly owned subsidiaryIn addition, after we started to consolidate the financial statements of Shanghai Ctrip, which holds domestic and cross-border travel agency licenses, air transport sales agency license; and

·Qunar from December 31, 2015, Beijing Qu Na Information Technology Co., Ltd., or Qunar Beijing, which holds the licenses, approvals and key assets such as mobile application and website that are essential to the business operations of Qunar.Qunar, may be deemed as our significant consolidated affiliated Chinese entity from accounting perspective, although Qunar continues to operate its businesses independently.

We formed Homeinns Hotel (Hong Kong) Limited, or Homeinns Hong Kong, in 2001 to expand our business to include the hotel management service. We spun off all of our interest in Homeinns Hong Kong in August 2003. Homeinns Hong Kong became a wholly owned subsidiary of Homeinns in June 2006. Homeinns undertook an initial public offering and its ADSs were listed on the NASDAQ Global Market in October 2006. During the period from September 12, 2008 to March 31, 2009, we purchased ADSs of Homeinns on the open market representing approximately 10% of the then total outstanding ordinary shares of Homeinns. In May 2009, we entered into a purchase agreement with Homeinns to acquire additional equity interest in Homeinns through a private placement of its ordinary shares for $50 million in cash. In connection with this private placement, we have also obtained certain demand, piggyback and Form F-3 registration rights from Homeinns. In June 2015, we, together with our co-founder and chief executive officer Mr. James Jianzhang Liang, our co-founder and independent director Mr. Neil Nanpeng Shen and certain other buyers, delivered a non-binding letter to Homeinns which proposes to acquire all of its outstanding ordinary shares not already owned by these buyers for a cash consideration of US$35.8 per ADS. In December 2015, Homeinns entered into an agreement and plan of merger with the special purpose vehicles formed by our consortium, pursuant to which one of our special purpose vehicles will merge with and into Homeinns with Homeinns continuing as the surviving company after the merger. Upon consummation of the merger, each of our shares in Homeinn will be converted into and become one validly issued, fully paid and non-assessable ordinary share, par value US$0.005 each, of the surviving company. Our aggregate equity interest in Homeinns was approximately 15% of the total outstanding ordinary shares of Homeinns as of December 31, 2015.

In March 2006, we formed a wholly owned subsidiary, C-Travel International Limited, an exempted company with limited liability incorporated in the Cayman Islands, in connection with our investment in a minority stake in ezTravel Co., Ltd., or ezTravel, an online travel service provider in Taiwan that offers packaged tours as well as hotel and airline ticket reservation services. In 2009, we consolidated ezTravel’s operating results because we had a controlling financial interest of ezTravel. The financial results of ezTravel are not significant to our company in the year ended December 31, 2015.

In April 2007, we formed a new wholly owned subsidiary, Ctrip Information Technology, in the PRC, in connection with the construction of our second customer service center in Nantong, Jiangsu Province, in anticipation of future business expansion.

In March 2010, we entered into a subscription agreement with China Lodging Group and a share purchase agreement with certain selling shareholders of China Lodging Group, pursuant to which we acquired an aggregate of 18,849,446 shares of China Lodging Group at a purchase price of $3.0625 per share, or a total consideration of $57.7 million in cash. In connection with this private placement, we have also obtained certain demand, piggyback and Form F-3 registration rights from China Lodging Group. In addition, in the same month we purchased 800,000 ADSs representing 3,200,000 shares of China Lodging Group in its initial public offering at a purchase price of $3.0625 per share, or a total purchase price of $9.8 million.

In May 2010, pursuant to a sale and purchase agreement dated February 3, 2010 among Wing On Travel (Holdings) Limited, C-Travel International Limited and Ctrip.com International, Ltd., we acquired 90% of the issued share capital of Wing On Travel’s travel service segment (operated through Wing On Travel’s subsidiary, HKWOT (BVI) Limited), for a total consideration of approximately US$88 million in cash, and began to consolidate its financial results since then. In February 2012, we entered into a sale and purchase agreement to purchase the remaining 10% of the issued share capital of HKWOT (BVI) Limited for a total consideration of US$9.4 million. The financial results of Wing On Travel were not significant to our company in the year ended December 31, 2015.

In October 2014, China Software Hotel Information System Co. acquired 100% shares of a technology company focusing on hotel customer reviews. In 2015, China Software Hotel Information System Co. changed the name to Beijing JointWisdom Information Technology Co., Ltd., or JointWisdom.

From time to time, we have selectively acquired or invested in businesses that complement our existing business, and will continue to do so in the future.future to expand and develop our business. See “Item 4.B. Information on the Company — Business Overview — Strategic Investments and Acquisitions” for material strategic investments and acquisitions over the past two years. Other than the material acquisitions or investments disclosed above, under “Item 4.4.B. Information on the Company — B. Business Overview — Strategic Investments and Acquisitions” or elsewhere in this annual report on Form 20-F, no acquisitions or investments was material to our businesses or financial results at the time we made the acquisition or investment.

In August 2014, we have expanded an existing commercial agreement with Priceline Group, to strengthen our global partnership. In addition, we issued US$500 million in aggregate principal amount of convertible notes duethe 2019 or the Priceline 2019 Notes to Priceline Group Treasury Company B.V., an indirect wholly ownedwholly-owned subsidiary of Priceline, Group and we granted Priceline Group a permission to acquire our shares in the open market over before August 2015, so that combined with shares issuable upon conversion of the convertible note,2019 Priceline GroupNotes, Priceline may hold up to 10% of our outstanding shares. Upon subscription of the convertible note,2019 Priceline GroupNotes, Priceline acquired the right to appoint an observer to our board of directors.

In May 2015, and December 2015 and September 2016, we issued US$250 million in aggregate principal amount of convertible notes duethe 2020 or the Priceline 2020 Notes, and US$500 million in aggregate principal amount of convertible notes duethe 2025 orPriceline Notes, and US$25 million in aggregate principal amount of the 2022 Priceline 2025 Notes, respectively, to an indirectthe same subsidiary of Priceline Group for its additional investment in us. Immediately following issuance of the US$500 million convertible notes2022 Priceline Notes in December 2015September 2016 and assuming full conversion of the convertible notes issued to Priceline Group according to their terms, Priceline Group will have beneficially owned securities representing approximately 10.5%8.89% of our outstanding shares based on the amendment to Schedule 13D filed by the subsidiary of Priceline Group on December 14, 2015.September 19, 2016. We have also extended permission to Priceline Group to increase its ownership in our company through the acquisition of ADSs in the open market so that, when combined with the shares issuable upon conversion of all of the Priceline notes, Priceline Group continues to be entitled to hold up to 15% of our outstanding shares (excluding shares that are beneficially owned by Priceline Group or its subsidiary due to any such entities’ ownership or conversion of the notes issued in December 2015)2025 Priceline Notes). We and Priceline Group have continued the existing commercial partnership, whereby accommodations inventory is cross-promoted between the brands. Concurrently with our issuance of the convertible notes to2025 Priceline GroupNotes in December 2015, Hillhouse also subscribed for and was issued US$500 million in aggregate principal amount of our convertible notes duethe 2025 or the Hillhouse 2025 Notes, in substantially the same terms as those issued to Priceline Group.Priceline.

In June 2015,September 2016, we concurrently completed an offering of 32,775,000 ADSs at US$70045.96 per ADS (taking into account of the fully exercised over-allotment option) and an offering of US$975 million in aggregate principal amount of convertible senior notes due 2020, or the 20202022 Notes and US$400 million in aggregate principal amount(taking into account of convertible senior notes due 2025, or the 2025 Notes.fully exercised over-allotment option). The notes2022 Notes were offered to qualified institutional buyers pursuant to Rule 144A under the Securities Act, and certain non-U.S. persons in compliance with Regulation S under the Securities Act. The 20202022 Notes will be convertible into ADSs based on an initial conversion rate of 9.194215.2688 ADSs per $1,000US$1,000 principal amount of notes (which is equivalent to an initial conversion price of approximately US$108.76 per ADS and represents an approximately 45.0% conversion premium over the closing trading price of the ADSs on June 18, 2015, which was US$37.51 per ADS). The 2025 Notes will be convertible into ADSs based on an initial conversion rate of 9.3555 ADSs per $1,000 principal amount of notes (which is equivalent to an initial conversion price of approximately US$106.8965.49 per ADS and represents an approximately 42.5% conversion premium over the closing trading price of the Company’s ADSs on June 18, 2015September 6, 2016 of US$37.5145.96 per ADS). The conversion rate for each of the 2020 Notes and the 20252022 Notes is subject to adjustment upon the occurrence of certain events. The 2020 Notes will bear interest at a rate of 1.0% per year, payable semiannually in arrears on January 1 and July 1 of each year, beginning on January 1, 2016. The 20202022 Notes will mature on July 1, 2020,September 15, 2022, unless previously repurchased or converted in accordance with their terms prior to such date. The 2025Concurrently with our ADS offering, we closed private placements of our ordinary shares with the respective subsidiaries of Baidu and Priceline at an aggregate investment amount of US$100 million and US$25 million, respectively, pursuant to exemptions from registration with SEC under Regulation S and Section 4(a)(2) of the Securities Act, respectively. In addition, concurrently with the closing of the 2022 Notes will bear interestoffering, we also closed a private placement of US$25 million aggregate principal amount of convertible notes due 2022 with a subsidiary of Priceline pursuant to an exemption from registration with SEC under Section 4(a)(2) of the Securities Act, in substantially the same terms as those of the 2022 Notes.

We offered inducements to the holders of the 2017 Notes and the 2018 Notes for early conversion. As a result, for the years ended December 31, 2016 and 2017, approximately US$26 million and US$352 million aggregate principal amount of the 2017 Notes and the 2018 Notes were early converted to approximately 2.6 million and 10.8 million ADSs, respectively, at a ratethe respective initial conversion rates of 1.99% per year, payable semiannuallythe 2017 Notes and the 2018 Notes. Such early conversion also resulted in arrears on January 1an early termination of the 2012 Purchased Call Option and July 1 of each year, beginning on January 1, 2016. The 2025 Notes will mature on July 1, 2025, unless previously repurchased or convertedthe 2013 Purchased Call Option, from which we received approximately US$12 million and US$100 million in accordance with their terms prior to such date.2016 and 2017, respectively.

Effective December 1, 2015, we changed our ADS to Class A ordinary share ratio from four (4) ADS representing one ordinary share to eight (8) ADSs representing one ordinary share. Unless otherwise indicated, ADSs and per ADS amount in this annual report have been retroactively adjusted to reflect the changes in ratio for all periods presented.

Our principal executive offices are located at 99 Fu Quan968 Jin Zhong Road, Shanghai 200335, People’s Republic of China, and our telephone number is (86-21)+86 (21) 3406-4880. Our agent for service of process in the United States is CT Corporation System. Our principal website address is www.ctrip.com. The information on our websites should not be deemed to be part of this annual report.

B.Business Overview

We are a leading travel service provider for accommodation reservation, transportation ticketing, packaged tours and corporate travel management in China. We aggregate hotel and transportation information to enable business and leisure travelers to make informed and cost-effective bookings. We help leisure travelers book tour packages and guided tours, and help corporate clients effectively manage their travel requirements. In addition, we offer a variety of other travel-related services, including but not limited to travelers’ reviews, attraction tickets, travel-related financing and car services, and travel insurance and visa services to meet the various booking and travelling needs of both leisure and business travelers. Since commencing operationsinception in 1999, we have become one of the best-known travel brands in China capable of providing truly one-stop travel services. Our leading market position has been further strengthened since our investment in Qunar, one of the leading mobile and online commerce platforms for travel in China. Qunar has been operating independently as a travel service provider after our investment.

We pioneered the development of a reservation and fulfillment infrastructure that enables our customers to:

·                  choose and reserve hotel rooms in cities throughout China and abroad;

·                  book and purchase transportation tickets for domestic and international flights and/or trains;

·                  choose and reserve packaged tours that include transportation and accommodations, as well as guided tours and other value-added services in some instances; and

·                  book and purchase other travel-related services for their leisure and business travels.

Meanwhile, Qunar continued its independent innovation of technology capabilities, leveraging its proprietary mobile applications, the complementary SaaS system and its search services, to provide more efficient and comprehensive services and accelerate its network effect.

We target our services primarily at business and leisure travelers in China who do not travel in groups.groups, catering for their increasing needs for both domestic and international travel with an emphasis on the latter to enable us to quickly adjust to the changing market environment. These types of travelers, who are referred to in the travel industry as FITs (frequentfrequent independent travelers)travelers, or FITs, and whom we refer to as independent travelers in this annual report, form a traditionally under-served yet fast-growing segment of the China travel market.market, and we saw opportunities of growth from this segment’s need for international travel. We act as an agent in substantially all of our transactions and generally do not take inventory risks with respect to the hotel rooms and transportation tickets booked through us. We derive our accommodation reservation, transportation ticketing and packaged-tour revenues mainly through commissions from our travel suppliers, primarily based on the transaction value of the rooms, transportation tickets and packaged-tour products, respectively, booked through our services.

We believe that we are the largest consolidator of hotel accommodations in China in terms of the number of room nights booked. As of December 31, 2015,2017, we had secured room supply relationships with approximately 359,000over 1.3 million hotels in China and approximately 690,000 hotels abroad, which covercovered a broad range of hotels in terms of priceprices and geographical location.locations. Through strategic cooperation arrangements with other leading online accommodation reservation service providers in recent years, we expanded our overseas hotel network by gaining access to more international hotels on these platforms through our accommodation reservation services. The quality and depth of our hotel supplier network enable us to offer our customers a wide selection of hotel accommodations. We believe our ability to offer reservations at highly rated hotels is particularly appealing to our customers. The hotel business of Qunar, which covers a wide range of hotels from upscale hotels to mass-market hotels to family-run and small boutique hotels, has begun to benefit from our hotel accommodation capabilities by accessing our high-end hotel supplies.

We believe that we are one of the largest consolidator of airline tickets and the top air tickets distribution agency in China in terms of the total number of airline tickets booked and sold.sold through us. Our airline ticket suppliers include all major ChinesePRC airlines and manyover 300 international airlines that operate flights originating in cities at home and abroad. Weabroad, and offer over 3 million flight routes, connecting over 5,000 cities in approximately 200 countries. Partnering with over 1,000 third-party travel service providers, we are among the few airline ticket consolidators in China that maintain a centralized reservation system and ticket fulfillment infrastructure covering substantially all of the economically prosperous regions of China. Our customers can make flight reservations on their chosen routes through mobile platform, internetInternet websites and customer service centers and arrange electronic payment. In addition, we provide the same levels of centralization and convenience to customers seeking to make reservationreservations on their chosen train and bus routes. We believe that we have realized a notable innovation in our transportation ticketing services, namely, our integrated product offering of air, train and bus tickets. International airline tickets sales volume through our platform grew significantly in 2017.

As long asOur continuing development of an advanced and centralized system further strengthens our cross-selling strategy. When users are searchingsearch for oneany of the three transportation products on our database, our system can automatically provide the recommendations to the other two transportation modes with the same dates, origins and destinations. This capability significantly helps our customers to streamline their decision-making process in searching for the most convenient, cost-efficient transportation. Moreover, Qunar’s proprietary technology systems and its own cross-selling capabilities provide alternatives to customers with diverse needs and preferences.

We also offer independent leisure travelers bundled packaged-tour products, including group tours, semi-group tours, and privatecustomized tours orand packaged tours with different transportation arrangements, such as cruise, busflights, cruises, buses or self-driving.car rental. We are the top packaged-tour operator in China in terms of online market share and most recognized brand in China’s outbound travel services. We provide integrated transportation and accommodation services through cooperation with around 12,000 platform partners, and offer a variety of value-added services including transportation at destinations, andas well as attraction tickets, local activities, insurance, visa services and tour guides. We offer customers one-stop services to meet their bookingneeds before, during and traveling needs.after their trips. We also provide high quality customer service,services, supplier management and customer relationship management services. Our packaged-tour products cover a variety of domestic and international destinations.

We have been building up a multifaceted ecosystem within the travel section, and offer our services to customers through an advanced transaction and service platform consisting of our mobile platform, multi-lingual websites and our centralized, 24-hour customer service centers. We have built up an industry-leading mobile platform which enhances user experience and user engagement. CumulativeWe have had billions of cumulative downloads for our mobile app grew from approximately 592 million asapplication by the end of December 31, 2014 to approximately 1.7 billion as of December 31, 2015.2017. In addition, our 24-hour service centers, which provide responsive and high quality customer services, further differentiate us from other online travel service providers. In the fiscal year ended December 31, 2015,2017, transactions effected through our mobile channel accounted for approximately 66%80% of our transaction orders.

We operate an open platform to further bridge the gap between travelers and travel suppliers with a diverse range of products and services. Travel suppliers ranging from airlines and third-party travel agencies to e-commerce websites offering travel products and services can list their inventories on our open platform to expand their business opportunities. We also offer high quality supplier management services and technology and financial support to enhance supplier experience and encourage supplier participation on the open platform. In addition, we offer high quality customer service to travelers for all the products and services they purchase through our open platform. We believe that our open platform helps us expand the number and types of products and services available to travelers and enhance our price competitiveness, and further build and strengthen the vibrant travel ecosystem on our open platform.

Our revenues are primarily generated from the accommodation reservation, transportation ticketing, packaged-tour services and corporate travel. For information on revenues attributable to our different products and services, see “Item 5.A. Operating and Financial Review and Prospects — Operating Results.”

Products and Services

We began offering accommodation reservation and transportation ticketing in October 1999. In 2015,2017, we derived approximately 40%35% of our revenues from the accommodation reservation business and 39%45% of our revenues from the transportation ticketing business. In addition, we offer other products and services including packaged tours, mostly bundled by us, that cover hotel, ticketing and transportation as well as corporate travel management services.

Accommodation Reservations.We act as an agent in substantially all of our hotel-related transactions. Our customers receive confirmed bookings and generally pay the hotels directly upon completion of their stays. In general, we pay no penalty to the hotels if our customers do not check in. For some of our hotel suppliers, we earn pre-negotiated fixed commissions on hotel rooms we sell. For other hotels, we have commission arrangements that we refer to as the “ratchet system,” whereby our commission rate per room night is adjusted upward with the increase in the volume of room nights we sell for such hotel during such month.

We contract with hotels for rooms under two agency models, the “guaranteed allotment” model and the “on-request” model. Under our agreements with our hotel suppliers, hotels are generally required to offer us prices that are equal to or lower than their published prices, and notify us in advance if they have promotional sales, so that we can lower our prices accordingly.

In addition to the agreements that we enter into with all of our hotel suppliers, we enter into a supplemental agreement with each of the hotel suppliers with which we have a guaranteed allotment arrangement. Pursuant to this agreement, a hotel guarantees us a specified number of available rooms every day, allowing us to provide instant confirmations on such rooms to our customers before notifying the hotel. The hotel is required to notify us in advance if it will not be able to make the guaranteed rooms available to our customers due to reasons beyond its control.

As of December 31, 2015, we had contracted with approximately 359,0002017, a significant number of our partnered hotels in China of which a majority havehad guaranteed room allotments, allowing us to confirm orders instantly and reserve rooms for our customersusers even during peak seasons and provide instant confirmation.seasons. Rooms booked in hotels with which we have a guaranteed allotment arrangement currently account for a significant part of our total hotel room transaction volume. With the remaining hotel suppliers, we book rooms on an “on-request” basis, meaning our ability to secure hotel rooms for our customers is subject to room availability at the time of booking.

Transportation Ticketing.  Transportation Ticketing revenues mainly represent revenues from reservation of air tickets, railway-tickets and other related services. We sell air tickets as an agent for all major domestic ChinesePRC airlines, such as Air China, China Eastern Airlines, China Southern Airlines and Hainan Airlines and many international airlines operating flights that originate from cities at home and abroad, such as Cathay Pacific, Singapore Airlines, American Airlines, Lufthansa, Emirates Airlines, Qantas Airways, Air France-KLM and Delta Air Lines. We also provide other related service to our customers, such as sales of aviation and train insurance, air-ticket delivery services, online check-in, and other value-added services, such as online seat selection and real-time flight dynamics.status. In 2017, we became the first and only travel provider allowing users to directly book with Big Bus Tours, the world’s largest operator of open-top sightseeing tours, which ensures users enjoy a one-stop booking experience that is not only hassle-free and efficient but is also a solution to local transportation difficulties.

Our customers can book tickets through our mobile platform, internetInternet websites and customer service centers and make payment electronically. The airline industry, including airline ticket pricing, is regulated by CAAC. Therefore, we have no discretion in offering discounts on the air tickets we sell.

Packaged TourTours.  We also offer independent leisure travelers bundled packaged-tour products, including group tours, semi-group tours, and privatecustomized tours orand packaged tours with different transportation arrangements, such as cruise, busflights, cruises, buses and self-driving.car rental. We provide integrated transportation and accommodations services and offer a variety of value-added services including transportation at destinations, andas well as attraction tickets, local activities, insurance, visa services and tour guides. We offer customers one-stop services to meet their bookingneeds before, during and traveling needs.after their trips. We also provide high quality customer service,services, supplier management and customer relationship management services. Our packaged-tour products cover a variety of domestic and international destinations.

Corporate Travel.We provide transportation ticket booking, accommodation reservation, packaged-tour services and packaged-tourother value-added services to our corporate clients to help them plan business travels in a cost-efficient way. In addition, we also provide our corporate clients with travel data collection and analysis, industry benchmark, cost saving analysis and travel management solutions. We have independently developed the Corporate Travel Management Systems, which is a comprehensive online platform integrating information maintenance, online booking, online authorization, online enquiry and travel report system.

Other Products and Services.  Our other products and services includeare primarily online advertising services,services.

We recently started a new partnership in December 2017 with Tennis Australia, the salegoverning body for tennis in Australia, which will allow Chinese fans to purchase Australian Open tickets directly through our online platform. In addition, in January 2018, we formed a partnership with the Priceline Group’s Open Table, which will allow our mobile application users to book tens of Property Management System, or PMS, and related maintenance service.thousands of restaurants across North America. Other products and services accounted for a small portion of our total revenues in 2015.2017.

Seasonality

Our business experiences fluctuations, reflecting seasonal variations in demand for travel services. See “Item 5.A. Operating Results,”and Financial Review and Prospects — Operating Results” for a discussion of seasonality in the travel industry.

Transaction and Service Platform

Our customers can reach us for their travel-related needs through either our mobile platform, our multi-lingual websites or our customer service centers. In 2015,2017, transactions executed through our websites and mobile platform combined further increased, accountingchannel accounted for more than 86%approximately 80% of our total transactions, compared with 80% in 2014.transaction orders. To improve the efficiency of our service platform and expand our business opportunities, we have made some technology improvements, such as enhanced international flight search capability, expanded payment methods and virtual desktop technology, which is deployed and in operation for our customer service centers.

Mobile Platform.Our mobile booking software providesapplication and other mobile access channels provide a one-stop travel platform to our customers who search for hotels, flight, travel, train,flights, trains, car rental, tickets and ticketother travel products, and completes bookings within minutes. Mobile applications enable our customers to make bookings more efficiently and have fueled our business growth in new direction. Our customers can also search for travel-related editorial content about destinations and travel tips through the mobile platform. Moreover, travelers can share their travel experience and micro-blogs with others through the Ctrip community. We first introduced mobile applications in 2010. Since then we have upgraded mobile applications, added new functions into it on a regular basis and engaged celebrities to promote our brands and mobile platform. CumulativeWe have had billions of cumulative downloads for Ctrip mobile app exceeded 1.7 billionapplication by December 31, 2015the end of 2017 with a significant portion of our hotel and air transactionticket transactions executed on it on a daily basis. Users can also enjoy similar convenient services by accesing our mobile platform via other mobile access channels, such as HTML5.

In 2013, we developed a corporate travel mobile app,application, which iswas the first of its kind in China and provides efficiency to corporate travelers. The appapplication has extensive booking capabilities that match the personal preference of the traveler with their companies’ travel policies. It also features “smart itinerary” and “travel update” functions to ensure users are informed immediately of any changes to their journey. Users of this appapplication may also enjoy also has 24-hours-a-day, seven-days-a-weekour call center support.support 24 hours a day, seven days a week. In 2017, we introduced mobile application for Trip.com, with which users can book hotels, air tickets and train tickets in 22 different currencies.

Internet Websites.  Through our Internet websites, we continue improving shopping experience in hotel accommodations, flight tickets, vacation packages, train tickets, and other travel products to our customers.

We have been constantly upgrading our open platform, so that our suppliers and partners are connected to Ctrip more efficiently. We have opened up our system to international partners, search engines, e-commerce websites and affiliated websites to expand business opportunities. We have made great efforts to enhance our price competitiveness by improving the efficiency of our IT system and by working closely with major airlines, numerous air ticketing agencies and accommodation suppliers, and thousands of destination business partners through the open platform.

We maintain our main website in Chinese at www.ctrip.com and our global website in English at english.ctrip.comwww.trip.com. Over time, we also established localized websites specifically targeting Hong Kong, Taiwan, United States, Singapore, Japan, Korea, France, Germany, Spain, Russia, Indonesia, Thailand, Australia, Italia and Malaysia markets.

We consolidate and organize travel-related information for our consumers, including user behavior data, hotel reviews, travel blogs and community forums. Destination guides and community users actively search for travel information on our websites. Our customers refer to editorial content for destination research and travel tips.

Customer Service Centers.  We have two customer service centers located in Shanghai and Nantong, respectively, and they operate 24 hours a day, seven days a week. Unlike some companies in the United States that outsource their customer service to third-party call centers, our customer service representatives are in-house travel specialists. All of our customer service representatives participated in a formal training program before commencing work.

Marketing and Brand Awareness

Through mobile and online marketing, brand promotion, cross-marketing, and customer rewards program, advertising and cross-marketing, we have created a strong Ctrip brand that is commonly associated in China with value travel products and services and superior customer service. We will continue to use our focused marketing strategy to further enhance awareness of our brand and acquire new customers.

Mobile Marketing.  We have cooperatedworked with somemajor Internet portals and leading mobile app marketing agenciesapplications in their respective sectors to advertise locally and telecommunications operatorsalso have worked with top smart phone manufacturers to increase the number of our app downloads and promote more activations and transactions. In addition, we are actively testing all kinds of innovative and rapid-growing mobile channels that are appealing to consumers.

Online Marketing.  We have contracted manywith majority of the leading Internetonline marketing channels, such as search engines, in Chinabrowsers and navigation websites, to prominently feature our websites and have cooperated with online companies to promote our services, as well as conducting public relations activities. We have purchased related keywords or directory links to direct potential customers to our websites.

AdvertisingBrand Promotion.  We advertiseconduct our brand campaigns through advertising on television, video streaming websites, targeted LCD display screens, radio stationsdisplays in public space, and subwaysbillboards at airport, railway station and bus station. We also conduct public relations activities in the major cities in China where we have a sales team. In 2013, we launched a multi-media campaign featuring a celebrity.work with celebrities and embed our brand and travel products into TV live shows, movies and other entertainment marketing channels. Based on our experience, we believe these are effective advertising methods for increasingways to enhance brand awareness and attractingattract new generation of customers.

Cross-Marketing.  We have entered into cross-marketing arrangements with major ChinesePRC domestic airlines, financial institutions, telecommunications service providers and other corporations. Our airline partners and financial institution partners recommend our products and services to members of their mileage programs or bank card holders. Customers can accumulate miles by booking air tickets through us, or earn Ctrip’s points by paying through co-branded credit cards.

Customer Rewards Program.  To secure our customers’ loyalty and further promote our Ctrip brand, we provide our customers with a customer rewards program. This program allows our customers to accumulate membership points calculated according to the services purchased by the customers. Our membership points have a fixed validity term and, before expiry, our customers may redeem these points for travel awards and other gifts.

Supplier Relationship Management

We have cultivated and maintained good relationships with our travel suppliers since our inception. We have a team of employees dedicated to enhance our relationship with existing travel suppliers and develop relationships with prospective travel suppliers.

Furthermore, we have developed an electronic confirmation system that enables participating hotel suppliers to receive our customer’s reservation information and confirm such reservation through our online interface with the hotel supplier.suppliers. We believe that the electronic confirmation system is a cost-effective and convenient way for hotels to interface with us. We have not had any material disputes with our travel suppliers with respect to the amount of commissions to which we were entitled.

Technology and Infrastructure

Since our inception, we have been able to support substantial growth in our offline and online traffic and transactions with our technology and infrastructure.

We provide 24-hours-a-day, seven-days-a-week travelerour customers sales and support service by website,mobile applications, by websites, by telephone or via e-mail, or by mobile apps. For purposes of providing high service level, we use24 hours a day, seven days a week. We maintain in-house call centers.centers to ensure high quality of our services. Our call centers are located in various locations, including in Shanghai and in Nantong. We have invested significantly in our call center technologies over years and provide top-notch services in China and Asia.

Our systems servers are housed in various locations, mainly in Shanghai and Nantong, and these system services are inter-linked among themselves. The performance of our systems servers are monitored and supported 24-hours-a-day, seven-days-a-week.24 hours a day, seven days a week. The web hosting facilities have their ownare equipped with back-up systemscapabilities and conduct daily backup functionsperform real-time mirror back-up and additional back-up for off-site storage.storage on a daily basis.

We access the Internet backbone via severalmaintain dedicated servers and high speed linesInternet access to provide fast responses to customer requests, load balance and data backup. The operation ofback-up. We regularly upgrade our customer service centers are powered by the servers provided by several leading backend server providers. We adopt hardware and software and procure security services to protect our servers against unauthorized access to data, or unauthorized alteration or destruction of data.

We believe that theour cutting-edge technology used throughout our quality of our services powered by technology differentiatedistinguishes us from our competitors in China. Our goal has been to build a reliable, scalable, and secure infrastructure to fully support our customer service center,centers, mobile and website operations and one-stop travel platform.

Competition

In the hotel consolidation market, we compete primarily with localdomestic and foreign invested consolidators of hotel accommodations. We also compete with new online travel search and service provider platforms;platforms, as well as traditional travel agencies. We believe thatwe are a leading online accomodation booking platform in China in terms of the volume of hotel room booking volume from FITs of our main competitors is significantly lower than ours.by FITs. However, as the travel business in China continues to grow, we may face competition from new players in the hotel consolidation market in China and foreign travel consolidators that may enter the China market.

In the transportation ticketing market, we compete primarily with other consolidators of air tickets with a multi-province airline ticket sales and fulfillment infrastructure in China. We also compete with new online travel search and service provider platforms. In the markets where we face local competition, our competitors generally conduct ticketing transactions in person, and not over the Internet or through customer service centers. Many local air-ticketing agencies are primarily involved in the wholesale business and do not directly serve individual travelers, who are our targeted customers. However, as the airline ticket distribution business continues to grow in China, we believe that more companies involved in the travel services industry may develop their services that compete with our transportation ticketing business.

Intellectual Property

Our intellectual property rights include trademarks and domain names associated with the name “Ctrip” and copyright and other rights associated with our websites, technology platform, booking software and other aspects of our business. We regard our intellectual property as a factor contributing to our success, although we are not dependent on any patents, intellectual property related contracts or licenses other than some commercial software licenses available to the general public. We rely on trademark and copyright law, trade secret protection, non-competition and confidentiality agreements with our employees to protect our intellectual property rights. We require our employees to enter into agreements to keep confidential all information relating to our customers, methods, business and trade secrets during and after their employment with us. Our employees are required to acknowledge and recognize that all inventions, trade secrets, works of authorship, developments and other processes made by them during their employment are our property.

Our major domain names isare ctrip.com, www.ctrip.comctrip.com.cn. It has and trip.com, all of which have been registered with www.markmonitor.com, and the domain name www.ctrip.com.cn with China Internet Network Information Center, a domain name registration service in China, andwe have full legal rights over these domain names. We conduct our business under the Ctrip brand name and logo. We have registered our major trademarks “Ctrip” and “携“携程” (Chinese characters for Ctrip) with the Trademark Office of the PRC State General Administration for Industry and Commerce, or SAIC. We have registered the trademark “Ctrip” and “携程” (Chinese characters for Ctrip)SAIC, with the Registrar of Trademarks in Hong Kong. We haveKong and also registered the trademark “Ctrip” and  “携程”(Chinese characters for Ctrip) with the United States Patent and Trademark Office. In 2009, we registered the trademark “携“携程” (Chinese characters for Ctrip) with the Taiwan Intellectual Property Office and with Direcção dos Serviços de Economia of Macau. In 2014  and 2015, weWe have also registered the trademark “Ctrip” and “携“携程” (Chinese characters for Ctrip) in Korea, European Union, Singapore, Swiss,Switzerland, Australia, New Zealand, Japan, and TheTurkey, Vietnam, the United Arab Emirates.

In 2012, we gotEmirates, Russia, Malaysia, Indonesia, the “World Travel Market Globe Award,” which is a global famous award,Philippines, India, South Africa, Brazil, the Kingdom of Cambodia and were also awarded the “Lifelong Honor,” which is the highest recognition of “Earphone Mic Cup.” In 2013, we were selected by WPP as one of the “BrandZ Top 50” in China and we were selected by Forbes Asia as one of “the Region’s Top 200 Small-and-mid Size Companies.” Thailand.

In 2015, we were recognized as “the Best Online Travel Agency in China” by Travel Weekly China. In 2016, we were awarded the “Most Valuable App” at the China App Development Forum and 2016 Most Popular App Awards Ceremony held in Beijing, China. Our customer service was recognized as the “2016 Best Call Center” at the 2016 Internet + China E-Commerce Summit Forum & China Call Center Development.” We were ranked in the “China’s top 10 most innovative companies” and the “10 most innovative companies in travel” lists of 2017 by Fast Company, a major financial business magazine in the United States. In 2017, we were recognized as “the Best Online Travel Agency in China” by Travel Weekly China and the “Most Honored Company” in the Technology, Media & Internet category by Institutional Investor in the 2017 All-Asia Executive Team Rankings.

Strategic Investments and Acquisitions

To maintain and strengthen our leading market position in China and to become a major travel service provider in the Greater China market, we constantly evaluate opportunities for strategic investments in, and acquisitions of, complementary businesses, assets and technologies and have made such investments and acquisitions from time to time. We have made the following material strategic investments and acquisitions over the past two years:years.

In December 2013During the period from September 2008 to May 2009, we have invested through open market purchases and August 2014, we entered into share purchase agreements to acquire minority stake of Easy Go Inc., or Easy Go, a leading online and mobile business car booking platform in China, by subscribing its Series B and Series C convertible preferred shares with a total consideration of US$53 million.

In December 2013 and April 2014, respectively, we subscribed Series E and Series E Plus convertible preferred shares of eHi Auto Services Limited, or eHi, one of the largest car rental companies in China, with a total consideration of approximately US$107 million. Immediately prior to completion of eHi’s initial public offering, these preferred shares were automatically converted into Class B common shares of eHi. In November 2014, we purchased, through a private placement transaction that was closed concurrentlyin Homeinns, a leading economy hotel chain in China. We later participated in various transactions with the initial public offering, US$10 million worth of Class A common shares of eHi at its initial public offering price,respect to Homeinns from time to time. In December 2016, in connection with our share exchange transaction with BTG and Homeinns, we subsequently sold these shares through a private transaction. Weexchanged our previously held an aggregateequity interest in Homeinns for 22% equity interest of approximately 14% of eHi’s total outstanding shares as of December 31, 2015.

In May 2014, we purchased, through a private placement transaction that was closed concurrently with the initial public offering, US$15 million worth of class A ordinary shares of Tuniu, at its initial public offering price. In December 2014, we purchased, in a separate transaction, an additional 3,731,034 newly issued Class A ordinary shares of Tuniu at an aggregate consideration of approximately US$15 million. In May 2015, we purchased 3,750,000 newly issued Class A ordinary shares of Tuniu at an aggregate consideration of approximately US$20 million. We held an aggregate equity interest of approximately 4% of Tuniu’s total outstanding shares as of December 31, 2015.

In April 2014, we acquired a minority stake in Tongcheng Network Technology Share Co., Ltd., or LY.com, a leading local attraction ticket service provider, for an aggregate cash consideration of RMB1.4 billion (US$228 million).

In September 2014, we acquired certain premises with an aggregate sellable gross floor area of 100,167 square meters and certain auxiliary facilities in Sky SOHO from SOHO (Shanghai) Investment Co., Ltd. for a total consideration of approximately RMB3 billion (US$490 million).

In November 2014, we formed a strategic partnership with Royal Caribbean, through a joint venture, which is designed to serve the PRC cruise market and operate one cruise ship, and we own 35% of the equity stake of the joint venture.

In January 2015, we completed an investment transaction acquiring a majority stake in Travelfusion Limited, a UK-based leading online Low Cost Carrier travel content aggregator and innovator of Direct Connect global distribution solutions.BTG.

In May 2015, we madeacquired approximately 38% share capital of eLong, Inc.. In May 2016, eLong, Inc. completed its “going-private” transaction and merger with eLong. In December 2017, eLong announced a merger with LY.com and the merger was consummated in March 2018 and we received an equity method investment in eLong through acquiring the sharesenlarged group.

As part of eLong from certain selling shareholders, including Expedia together with several other investors. We acquired a 38% equity stakeour ongoing strategy to invest in eLong for a total purchase price of approximately US$422 million. In addition, wecomplementary business and Expedia agreed to cooperate with each other to allowfurther expand our respective customers to benefit from certain travel product offerings, for specified geographic markets. In August 2015, we, together with Tencent Holdings Limited, or Tencent, and certain other buyers, delivered a non-binding letter to eLong which proposes to acquire all of its outstanding ordinary shares not already owned by these buyers for a cash consideration of US$18.00 per ADS. In February 2016, eLong entered into an agreement and plan of merger with China E-dragon Holdings Limited, the special purpose vehicle formed by the consortium led by Tencent, and China E-dragon Mergersub Limited, a wholly owned subsidiary of China E-dragon Holdings Limited, pursuant to which China E-dragon Holdings Limited will acquire eLong. At the closing of the transaction, China E-dragon Holdings Limited will be owned by certain of eLong’s existing shareholders, including us, along with Seagull Limited and certain management members of eLong.

Inin October 2015, we completed a share exchange transaction with Baidu, pursuant to which Baidu exchanged 178,702,519approximately 179 million Class A ordinary shares and 11,450,000approximately 11 million Class B ordinary shares of Qunar, beneficially owned by Baidu prior to the consummation of the transaction for our 11,488,381approximately 11 million newly-issued ordinary shares. Immediately after the closing of the transaction, Baidu owned our ordinary shares representing approximately 25% of our aggregate voting interest, and we owned Class B ordinary shares of Qunar representing approximately 45% of Qunar’s aggregate voting interest. Robin Yanhong Li, Baidu’s chairman and chief executive officer, and Tony Yip, vice president head of investments, mergers and acquisitions of Baidu, have been appointed to our board of directors.

In October 2017, Tony Yip resigned as our director and Herman Yu, chief financial officer of Baidu, was later appointed by Baidu as a successor director. As a result of the share exchange transaction with Baidu, we have becomebecame a significant shareholder of Qunar. Following our investment in Qunar, Qunar continues to operate its business independently. We have certain business cooperation arrangements with Qunar.

We believe that it would be in the interest of our shareholders and us to provide equity incentives to Qunar employees to align their interests with those of Qunar and its shareholders, including us. To this end, in December 2015,In connection with our transaction with Baidu, we agreed to issue a total of approximately 5 million ordinary shares to certain special purpose vehicles holding shares solely for the benefit of Qunar employees. In DecemberThe issuance of such Ctrip shares to Qunar employees is conditional upon the surrender by such employees of any Qunar securities held by or granted to them. As consideration, we received Class B ordinary shares of Qunar and directly injected these shares to a third-party investment entity dedicated to investing in business in China. Under U.S. GAAP, as a result of our share exchange with Baidu in October 2015 and March 2016, we offered approximately 4.0 million ordinary shares represented by ADSs to three special purpose vehicles, each of which holds the ADSs solelyshare issuance for the benefit of Qunar employees. As a result of the transactionemployees in December 2015, we began to consolidate Qunar’s financial statements from December 31, 2015 from an accounting perspective. Future receiptIn June 2016, the board of directors of Qunar received a non-binding going-private proposal, dated June 23, 2016, from Ocean Management Limited to acquire all outstanding ordinary shares of Qunar not beneficially owned by Qunar’s shareholders accounting for a majority in voting power of Qunar employeesfor US$30.39 per ADS, or US$10.13 per ordinary share, of our shares will be upon satisfactionQunar in cash. The board of legaldirectors of Qunar formed a special committee to consider the going-private proposal and contractual conditions, including the conditiontransaction contemplated by such proposal. In October 2016, Qunar announced that anyit had entered into definitive merger agreement for the going-private transaction. Qunar securities heldannounced that its going-private transaction was approved by or granted to any Qunar employee must have been surrendered before the employee receives our shares.its shareholders and later completed in February 2017.

In late 2015 and early 2016, weWe agreed to make certain investments, in the form of limited partnership contribution or other financing arrangements respectively, in several non-U.S. investment entities, whichwith an aggregate fair value of approximately US$2.9 billion and US$0.4 billion in 2016 and 2017. These entities are managed or owned by parties unaffiliated with each other and unaffiliated with us and are dedicated to investing in businesses in China. In January 2016, we issued a total number of approximately 5.4 million ordinary shares, including 2,661,967 ordinary shares represented by ADSs, and provided capital contribution or financial support in a total amount of approximately US$1.3 billion in cash to some of these non-U.S.These investment entities in accordance with ASC810 underhave spent the investments to acquire the equity interest of Qunar that were not held by us through privately negotiated transactions. Under U.S. GAAP. We consolidatedGAAP, we consolidate the financial statements of these non-U.S. investment entities and as such these cash outflows and share issuances will be eliminated in consolidation. In March 2016, we further issuedfrom an aggregate of 395,106 ordinary shares represented by ADSs to certain of these non-U.S. investment entities. These non-U.S. entities have, in the aggregate, acquired a significant minority stake of Qunar from Qunar’s shareholders through privately negotiated transactions, using cash and/or our ordinary shares as purchase consideration.accounting perspective.

In January 2016, we invested US$180 million in MakeMyTrip Limited (NASDAQ: MMYT), orto purchase the convertible bonds of MakeMyTrip, India’s largest online travel company, via convertible bonds.which were subsequently converted to approximately 10% equity interest in MakeMyTrip in October 2016. In addition,May 2017, we further invested approximately US$33 million in MakeMyTrip has granted us permission to acquire MakeMyTrip shares inby subscribing for 916,666 of its ordinary shares. As of December 31, 2017, based on the open market so that combined with shares convertible under the convertible bonds,price, we may beneficially own up to 26.6% of MakeMyTrip’s outstanding shares. Following completion ofre-measured the investment we appointedat a director to the MakeMyTrip boardfair value of directors.RMB2.1 billion.

In April 2016, we announced strategic collaboration with China Eastern Air Holding Company,Airlines (SSE: 600115, SEHK: 00670, NYSE: CEA), one of China’s three major air transportation groups, on a broad range of products and services, andservices. In June 2016, we agreed to invest RMB3invested approximately RMB3.0 billion in theapproximately 466 million A shares of China Eastern Airlines (SSE: 600115, SEHK: 00670, NYSE: CEA) throughin a private placementplacement.

In December 2016, we consummated an acquisition transaction whereby shares held by nearly all the shareholders of Skyscanner, a leading global travel search site headquartered in Edinburgh, the United Kingdom, were acquired by Ctrip. The total purchase consideration for the acquisition of Skyscanner was approximately £1.4 billion, which consists of £1.2 billion in cash and the remainder in our ordinary shares. After the acquisition, the then incumbent management team of Skyscanner continues to manage its operations independently as part of the Ctrip group.

PRC Government Regulations

Current PRC laws and regulations impose substantial restrictions on foreign ownership of the air-ticketing, travel agency advertising and value-added telecommunications businesses in China. As a result, we conduct these businesses in China through contractual arrangements with our consolidated affiliated PRCChinese entities as well as certain independent air-ticketing agencies and travel agencies. Our vice chairmanSome of the boardour directors and president, Min Fan and our officers, Tao Yang, Qi Shi, Maohua Sun, Hui Cao and Hui Wang all of whom are PRC citizens, directly or indirectly own all or most of the equity interests in our consolidated affiliated Chinese entities as of the date of this annual report.

According to our PRC counsel, Commerce & Finance Law Offices, the ownership structures, as described in this annual report, comply with all existing PRC laws, rules and regulations.

Restrictions on Foreign Ownership

Air-ticketing.  According to the Rules on CognizanceAdministrative Measure of Qualification forForeign Investment in Civil Aviation, Transporting Marketing AgenciesAir Transportation Sales Agent Qualification Accreditation Measures (2006) and relevant foreign investment regulations regarding civil aviationair transportation business, a foreign investor currently cannot own 100% of an air- ticketingair-ticketing agency in China, except for Hong Kong and Macau aviation marketing agencies.air transportation sales agents. In addition, foreign-invested air-ticketing agencies are not permitted to sell passenger airlineair tickets for domestic flights in China, except for Hong Kong and Macau aviation marketing agencies.air transportation sales agents. Subsequently, the Air Transportation Sales Agent Qualification Accreditation Measures was revised in 2015, which does not prohibit explicitly foreign-invested air-ticketing agencies from selling passenger air tickets for domestic flights and a supplement regulation to Administrative Measure of Foreign Investment in Civil Aviation was promulgated in 2017, which further allows the foreign investor to establish an entity in free trade zone area as air-ticketing agency.

Travel Agency.  Currently, foreign investors have beenare permitted to establish or own a travel agency upon the approval of the PRC government approval, subject to considerable restrictions as toon its scope of business. For examples, under the current Travel Agency Regulations, which became effective on May 1, 2009 as amended subsequently, foreign-invested travel agencies cannot arrange for mainlandPRC residents to travel overseas or to Hong Kong, Macau andor Taiwan, unless otherwise decided by the State Council or allowed under the Free Trade Agreementany applicable free trade agreement executed by the PRC government or according to the Closer Economic Partnership Arrangement between Mainlandmainland China and Hong Kong or Macau, (“CEPA”).or CEPA. According to the CEPAs, starting from January 1, 2013, travel agencies in which qualified Hong Kong or Macau qualified investors hold an interest are permitted to arrange group traveltours for thePRC residents in local regions from mainland China to Hong Kong and Macau andMacau. Moreover, on a trial basis, one qualified sino-foreignSino-foreign joint venture, in which qualified Hong Kong qualified investors hold an interest, and one qualified sino-foreignSino-foreign joint venture, in which qualified Macau qualified investors hold an interest, arewere permitted to arrange group traveltours for domesticPRC residents to travel overseas which does not include(excluding Hong Kong, Macau and Taiwan.Taiwan). On August 29, 2010, the PRC National Tourism Administration, or NTA, and the Ministry of CommerceMOFCOM further promulgated the Temporary Administration RulesInterim Measures for Supervising Pilot Operation of Overseas Travel Business by Sino-Foreign Joint InvestedVenture Travel Agencies, to Operate Trip to Overseas Business for Trial, according to which the State Tourism AdministrationNTA may choose and approve certain qualified sino-foreignSino-foreign joint venture travel agencies to operate business of arranging mainland residentPRC residents travelling to overseas destinations, Hong Kong and Macau (excluding Taiwan), on a trial basis, except for Taiwan.basis. In 2017, China (Shanghai) Pilot Free Trade Zone has implemented a pilot project that allows the wholly foreign-owned travel agencies registered in China (Shanghai) Pilot Free Trade Zone and satisfied with required conditions to operate outbound tourism business. One of our subsidiaries, Wancheng, has obtained the approval in 2017 to operate outbound tourism business from National Tourism Administration with the pilot period of three years.

Online Advertising.  The principal regulationsregulation governing foreign ownership offoreign-invested advertising agencies in China are the Administrative Measures for Foreign Invested Advertising Enterprise, which was abolished due to the issuance of Foreign Investment Industrial Guidance Catalogue as amended in 2015,(2015 Revision), or the Catalogue, which came into effect on April 10, 2015. Under this catalogue,the Catalogue, foreign investors are allowed to own 100% of an advertising agency in China subject to certain qualification requirements. However, for thoseforeign investment in advertising agencies that provide online advertising service,services is still subject to restrictions of foreign ownership restrictions oninvestment in the value-added telecommunications business are still applicable.business.

Value-added Telecommunications Business License.  The principal regulations governing foreign ownership ofinvestment in the value-added telecommunications service provision business in China include:

·                  Administrative Rules for Foreign Investments inInvestment Industrial Guidance Catalogue;

·                  Telecommunications Enterprises (2008 Revision);Regulations; and

·                  Administrative Provisions on Foreign Investment Industrial Guidance Catalogue (2015).Invested Telecommunications Enterprises.

Under these regulations, a foreign entity is prohibited from owning more than 50% of a PRC entity that provides value-added telecommunications services.services except for commercial e-commerce business, which allows 100% foreign investment.

In July 2006, the MIIT issued the Circular on IntensifyingStrengthening the Administration of Foreign Investment in Value-added Telecommunication Business, which statesstipulates that a domestic company that holds ana value-added telecommunications business license is prohibited from leasing, transferring or selling the license to foreign investors in any form, and prohibited from providing any assistance in forms of resources, sites or facilities to foreign investors that conduct value-added telecommunications business illegally in China. Furthermore, the relevant trademarks and domain names used in the value-added telecommunications business shallmust be owned by the localdomestic value-added telecommunications license holder.holders. Due to the lack of further necessary interpretation from the regulator,by MIIT, it remains unclear what impact the above circular will have on us or other ChinesePRC Internet companies that have adopted the same or similar corporate and contractual structures as ours.

General Regulation of Businesses

Tourism Law.  On April 25, 2013, the Standing Committee of the National People’s Congress ofNPC issued the PRC issued the Tourism Law, of the PRC, or the Tourism Law, which took effect on October 1, 2013.2013 and was amended in 2016. The Tourism Law aims to protect the tourists’ legal rights, regulate tourismtravel market and promote the development of tourismtravel industry, and sets forth specific requirements for the operation of travel agencies. The travelTravel agencies are prohibited from (i) leasing, lending or illegally transferring travel agency operation licenses theor otherwise disseminating untrue or inaccurate information published by travel agencies to attractwhen soliciting customers and organize customers must be true and accurate,organizing tours, (ii) conducting any false publicity to mislead customers, (iii) arranging visits to or participation in any project or activity in violation of thePRC laws and regulations of the PRC or social morality, (iv) organizing tourism activitiestours at unreasonably low price to induce or cheat tourists, andor obtaining unlawful profits such as kickbacks, by shopping arrangements or tour items paid separately, and (v) specifying shopping venueschanging or arranging tour items paid separately when organizingceasing scheduled itineraries without reasons and receivingforcing the tourists except for those negotiated byto participate in other activities against the parties or demanded by the customers, which in any event should not affect the itinerarieswill of other customers.tourists. In addition, travel agencies shall concludemust enter into contracts with customers for tourism activities;travel services; and before the start of the itinerary, customersa tour starts, a customer may transfer theirassign his personal rights and obligations in the package toura packaged-tour contract to any third person, whom the travel agency shall notcannot refuse without justifiable reasons, andcause, as long as any increased fees shallfee increase will be borne by the customer and the relevant third persons.person. Accordingly, travel agencies may be subject to civil liabilities for failing to fulfill the obligations discussed above, which include rectification, issuance of a warning, confiscation of any illegal income, imposition of a fine, an order to cease business operation, or revocation of its travel agency permit. Furthermore, if a travel agency arranges shopping venues in violation of the Tourism Law, customers have the right, within 30 days after the end of the itinerary, to demand that the travel agencies handle the return of any purchased goods and make advance payment for the returned goods, or return the fees for any tour items paid separately.