Sunlands Technology (STG) 20-F 24 Apr 20 2019 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2019shares
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Sunlands Technology Group
Entity Central Index Key	0001723935
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Document Registration Statement	false
Document Accounting Standard	U.S. GAAP
Entity File Number	001-38423
Entity Incorporation, State or Country Code	E9
Entity Address, Address Line One	Building 4-6, Chaolai Science Park
Entity Address, Address Line Two	No.36 Chuangyuan Road
Entity Address, Address Line Three	Chaoyang District
Entity Address, City or Town	Beijing
Entity Address, Country	CN
Entity Address, Postal Zip Code	100012
Class A Ordinary Shares
Entity Common Stock, Shares Outstanding	1,728,006
Title of 12(b) Security	Class A ordinary shares, par value US$0.00005 per share
Security Exchange Name	NYSE
No Trading Symbol Flag	true
Class B Ordinary Shares
Entity Common Stock, Shares Outstanding	826,389
Class C Ordinary Shares
Entity Common Stock, Shares Outstanding	4,258,686
American Depositary Shares
Title of 12(b) Security	American depositary shares, each 25 ADS represent one Class A ordinary share
Trading Symbol	STG
Security Exchange Name	NYSE
Business Contact
Contact Personnel Name	Yipeng Li
Entity Address, Address Line One	Building 4-6, Chaolai Science Park
Entity Address, Address Line Two	No.36 Chuangyuan Road
Entity Address, Address Line Three	Chaoyang District
Entity Address, City or Town	Beijing
Entity Address, Country	CN
Entity Address, Postal Zip Code	100012
City Area Code	10
Local Phone Number	52413738
Contact Personnel Email Address	liyipeng@sunlands.com

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Current assets
Cash and cash equivalents	¥ 1,402,226	$ 201,417	¥ 1,248,810
Short-term investments	217,640	31,262	1,028,564
Prepaid expenses and other current assets	180,881	25,982	124,908
Deferred costs, current	243,447	34,969	180,657
Total current assets	2,044,194	293,630	2,582,939
Non-current assets
Property and equipment, net	545,675	78,381	559,511
Intangible assets, net	1,176	169	1,369
Right-of-use assets	598,991	86,040	0
Deferred costs, non-current	205,488	29,517	146,610
Long-term investments	40,026	5,749	30,009
Deferred tax assets	85,513	12,283
Other non-current assets	447,639	64,299	418,700
Total non-current assets	1,924,508	276,438	1,156,199
TOTAL ASSETS	3,968,702	570,068	3,739,138
Current liabilities
Accrued expenses and other current liabilities (including accrued expenses and other current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB241,204 and RMB209,727 as of December 31, 2018 and 2019, respectively)	435,225	62,516	455,284
Deferred revenue, current (including deferred revenue, current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,765,085 and RMB1,162,938 as of December 31, 2018 and 2019, respectively)	1,670,076	239,891	1,765,085
Lease liabilities, current (including lease liabilities, current portion of the consolidated VIEs without recourse to Sunlands Technology Group of nil and RMB22,659 as of December 31, 2018 and December 31, 2019, respectively)	40,236	5,780
Payables to acquire buildings (including payables to acquire buildings of the consolidated VIEs without recourse to Sunlands Technology Group of nil and nil as of December 31, 2018 and December 31, 2019, respectively)	61,540	8,840	61,540
Long-term debt, current portion (including long-term debt, current portion of the consolidated VIEs without recourse to Sunlands Technology Group of nil and nil as of December 31, 2018 and December 31, 2019, respectively)	32,500	4,668	32,500
Total current liabilities	2,239,577	321,695	2,314,409
Non-current liabilities
Deferred revenue, non-current (including deferred revenue, non-current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,520,940 and RMB1,096,482 as of December 31, 2018 and 2019, respectively)	1,558,694	223,892	1,520,940
Lease liabilities, non-current (including lease liabilities, non-current portion of the consolidated VIEs without recourse to Sunlands Technology Group of nil and RMB358,467 as of December 31, 2018 and December 31, 2019, respectively)	616,246	88,518
Deferred tax liabilities(including deferred tax liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of nil and RMB4,415 as of December 31, 2018 and December 31, 2019, respectively)	87,954	12,634
Other non-current liabilities (including other non-current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB135 and RMB135 as of December 31, 2018 and December 31, 2019, respectively)	11,469	1,647	17,147
Long-term debt, non-current portion (including long-term debt, non-current portion of the consolidated VIEs without recourse to Sunlands Technology Group of nil and nil as of December 31, 2018 and December 31, 2019, respectively)	193,125	27,741	225,625
Total non-current liabilities	2,467,488	354,432	1,763,712
TOTAL LIABILITIES	4,707,065	676,127	4,078,121
COMMITMENTS AND CONTINGENCIES (Note 20)
SHAREHOLDERS’ DEFICIT
Treasury stock	0	0	0
Additional paid-in capital	2,363,999	339,567	2,391,822
Accumulated other comprehensive income	142,435	20,460	118,827
Accumulated deficit	(3,244,587)	(466,056)	(2,849,770)
Total Sunlands Technology Group shareholders’ deficit	(738,151)	(106,029)	(339,119)
Noncontrolling interest	(212)	(30)	136
TOTAL SHAREHOLDERS’ DEFICIT	(738,363)	(106,059)	(338,983)
TOTAL LIABILITIES AND SHAREHOLDERS’ DEFICIT	3,968,702	570,068	3,739,138
Class B Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	0	$ 0	0
Class A Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	1		1
TOTAL SHAREHOLDERS’ DEFICIT	1		1
Class C Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	1		1
TOTAL SHAREHOLDERS’ DEFICIT	¥ 1		¥ 1

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2018$ / shares	Mar. 31, 2018shares	Sep. 18, 2015$ / sharesshares	Sep. 18, 2015¥ / sharesshares
Accrued expenses and other current liabilities	¥ 435,225	$ 62,516	¥ 455,284
Deferred revenue, current	1,670,076	239,891	1,765,085
Lease liabilities, current	40,236	5,780
Payables to acquire buildings	61,540	8,840	61,540
Long-term debt, current	32,500	4,668	32,500
Deferred revenue, non-current	1,558,694	223,892	1,520,940
Lease liabilities, non-current	616,246	88,518
Deferred tax liabilities	87,954	12,634
Other non-current liabilities	11,469	1,647	17,147
Long-term debt, non-current	¥ 193,125	$ 27,741	¥ 225,625
Ordinary shares, par value | (per share)						$ 0.00005	¥ 0.0003
Ordinary shares, shares authorized						1,000,000,000	1,000,000,000
Ordinary shares, shares issued						1	1
Ordinary shares, shares outstanding					4,329,000
Class A Ordinary Shares
Ordinary shares, par value | $ / shares		$ 0.00005		$ 0.00005
Ordinary shares, shares authorized	796,062,195	796,062,195	796,062,195
Ordinary shares, shares issued	1,830,183	1,830,183	1,818,383
Ordinary shares, shares outstanding	1,728,006	1,728,006	1,773,301		63,714
Class B Ordinary Shares
Ordinary shares, par value | $ / shares		$ 0.00005		0.00005
Ordinary shares, shares authorized	826,389	826,389	826,389
Ordinary shares, shares issued	826,389	826,389	826,389
Ordinary shares, shares outstanding	826,389	826,389	826,389
Class C Ordinary Shares
Ordinary shares, par value | $ / shares		$ 0.00005		$ 0.00005
Ordinary shares, shares authorized	203,111,416	203,111,416	203,111,416
Ordinary shares, shares issued	4,258,686	4,258,686	4,265,286
Ordinary shares, shares outstanding	4,258,686	4,258,686	4,265,286		4,265,286
VIEs
Accrued expenses and other current liabilities | ¥	¥ 209,727		¥ 241,204
Deferred revenue, current | ¥	1,162,938		1,765,085
Lease liabilities, current | ¥	22,659
Deferred revenue, non-current | ¥	1,096,482		1,520,940
Lease liabilities, non-current | ¥	358,467
Deferred tax liabilities | ¥	4,415
Other non-current liabilities | ¥	¥ 135		¥ 135

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS ¥ in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2019CNY (¥)¥ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018CNY (¥)¥ / sharesshares	Dec. 31, 2017CNY (¥)¥ / sharesshares
Income Statement [Abstract]
Net revenues		¥ 2,193,902	$ 315,134	¥ 1,973,985	¥ 970,162
Cost of revenues (including share-based compensation expenses of RMB19,244, RMB314 and RMB317 for the years ended December 31, 2017, 2018 and 2019, respectively)		(396,316)	(56,927)	(330,376)	(170,261)
Gross profit		1,797,586	258,207	1,643,609	799,901
Operating expenses
Sales and marketing expenses (including share-based compensation expenses of RMB75,237, RMB773 and RMB674 for the years ended December 31, 2017, 2018 and 2019, respectively)		(1,792,285)	(257,446)	(2,152,830)	(1,351,811)
Product development expenses		(101,717)	(14,611)	(76,022)	(32,862)
General and administrative expenses (including share-based compensation expenses of RMB194,282, RMB2,764 and RMB1,979 for the years ended December 31, 2017, 2018 and 2019, respectively)		(363,307)	(52,186)	(443,691)	(342,906)
Total operating expenses		(2,257,309)	(324,243)	(2,672,543)	(1,727,579)
Loss from operations		(459,723)	(66,036)	(1,028,934)	(927,678)
Interest income		60,166	8,642	70,355	13,578
Interest expense		(14,312)	(2,056)	(2,171)
Other income, net		21,280	3,057	32,090	276
Loss before income tax expenses		(392,589)	(56,393)	(928,660)	(913,824)
Income tax expenses		(2,440)	(350)	0	0
(Loss)/gain from equity method investments		(136)	(20)	1,710	(4,890)
Net loss		(395,165)	(56,763)	(926,950)	(918,714)
Less: Net (loss)/gain attributable to noncontrolling interest		(348)	(50)	72	(136)
Net loss attributable to Sunlands Technology Group		¥ (394,817)	$ (56,713)	¥ (927,022)	¥ (918,578)
Net loss per share attributable to ordinary shareholders of Sunlands Technology Group:
Basic and diluted | (per share)		¥ (57.81)	$ (8.30)	¥ (147.27)	¥ (232.80)
Weighted average shares used in calculating net loss per ordinary share:
Basic and diluted	[1]	6,830,058	6,830,058	6,294,870	3,945,864
[1]	Each 25 American depositary shares ("ADSs") represents one of the Company's Class A ordinary shares.

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allocated Share-based Compensation Expense	¥ 2,970	¥ 3,851	¥ 288,763
Cost of Revenues
Allocated Share-based Compensation Expense	317	314	19,244
Selling and Marketing Expense
Allocated Share-based Compensation Expense	674	773	75,237
General and Administrative Expense
Allocated Share-based Compensation Expense	¥ 1,979	¥ 2,764	¥ 194,282

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Statement Of Income And Comprehensive Income [Abstract]
Net loss	¥ (395,165)	$ (56,763)	¥ (926,950)	¥ (918,714)
Other comprehensive (loss)/income, net of tax effect of nil:
Change in cumulative foreign currency translation adjustments	23,608	3,391	127,586	(8,759)
Total comprehensive loss	(371,557)	(53,372)	(799,364)	(927,473)
Less: comprehensive (loss)/income attributable to noncontrolling interest	(348)	(50)	72	(136)
Comprehensive loss attributable to Sunlands Technology Group	¥ (371,209)	$ (53,322)	¥ (799,436)	¥ (927,337)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' DEFICIT ¥ in Thousands, $ in Thousands		CNY (¥)	USD ($)	Class A Ordinary SharesCNY (¥)shares	Class B Ordinary Sharesshares	Class C Ordinary SharesCNY (¥)shares	Ordinary SharesCNY (¥)shares	Additional Paid-in CapitalCNY (¥)	Additional Paid-in CapitalUSD ($)	Treasury Stockshares	Accumulated Other Comprehensive (Loss)/IncomeCNY (¥)	Accumulated Other Comprehensive (Loss)/IncomeUSD ($)	Accumulated DeficitCNY (¥)	Accumulated DeficitUSD ($)	Total Sunlands Technology Group Shareholders' DeficitCNY (¥)	Total Sunlands Technology Group Shareholders' DeficitUSD ($)	Noncontrolling InterestCNY (¥)	Noncontrolling InterestUSD ($)
Balances at Dec. 31, 2016		¥ (888,955)					¥ 1	¥ 30,911					¥ (919,867)		¥ (888,955)
Balances (in shares) at Dec. 31, 2016 | shares							3,818,618
Net loss for the year		(918,714)											(918,578)		(918,578)		¥ (136)
Capital contribution from a noncontrolling shareholder		200															200
Repurchase of equity from shareholders	[1]	(71,303)						(30,000)					(41,303)		(71,303)
Cash dividend to a Series A convertible redeemable preferred shareholder		(43,000)											(43,000)		(43,000)
Shares issuance in relation to share-based compensation, shares | shares							510,382
Share-based compensation		288,763						288,763							288,763
Foreign currency translation adjustments		(8,759)									¥ (8,759)				(8,759)
Balances at Dec. 31, 2017		(1,641,768)					¥ 1	289,674			(8,759)		(1,922,748)		(1,641,832)		64
Balances (in shares) at Dec. 31, 2017 | shares							4,329,000
Net loss for the year		(926,950)											(927,022)		(927,022)		72
Issuance of ordinary shares, net of issuance cost of 80,128		1,109,517						1,109,517							1,109,517
Issuance of ordinary shares, net of issuance cost, shares | shares				659,131
Conversion of convertible redeemable preferred shares upon initial public offering (Note 13)		1,024,709		¥ 1		¥ 1	¥ (1)	1,024,708							1,024,709
Conversion of convertible redeemable preferred shares upon initial public offering (Note 13), shares | shares				1,159,252	826,389	4,265,286	(4,329,000)
Share repurchase		(34,828)						(34,828)							(34,828)
Share repurchase, shares | shares				(45,082)						45,082
Share-based compensation		2,751						2,751							2,751
Foreign currency translation adjustments		127,586									127,586				127,586
Balances at Dec. 31, 2018		(338,983)		¥ 1		¥ 1		2,391,822			118,827		(2,849,770)		(339,119)		136
Balances (in shares) at Dec. 31, 2018 | shares				1,773,301	826,389	4,265,286				45,082
Net loss for the year		(395,165)	$ (56,763)										(394,817)		(394,817)		(348)
Conversion Class C Ordinary shares to Class A Ordinary shares (Note 13), shares | shares				6,600		(6,600)
Share repurchase		(30,793)						(30,793)							(30,793)
Share repurchase, shares | shares				(51,895)						51,895
Share-based compensation		2,970						2,970							2,970
Foreign currency translation adjustments		23,608	3,391								23,608				23,608
Balances at Dec. 31, 2019		¥ (738,363)	$ (106,059)	¥ 1		¥ 1		¥ 2,363,999	$ 339,567		¥ 142,435	$ 20,460	¥ (3,244,587)	$ (466,056)	¥ (738,151)	$ (106,029)	¥ (212)	$ (30)
Balances (in shares) at Dec. 31, 2019 | shares				1,728,006	826,389	4,258,686				96,977
[1]	In July 2017, Beijing Shangde Online Education Technology Co., Ltd. (“Beijing Sunlands”) repurchased equity interests held by certain shareholders at a total cash consideration of RMB71,303. Such equity interests of Beijing Sunlands were originally acquired at a cost of RMB30,000.

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' DEFICIT (Parenthetical) - CNY (¥) ¥ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2017	Dec. 31, 2018
Issuance cost		¥ 80,128
Beijing Sunlands
Repurchased equity interests	¥ 71,303
Cost of acquired stock	¥ 30,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASHFLOWS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	¥ (395,165)	$ (56,763)	¥ (926,950)	¥ (918,714)
Adjustments to reconcile net loss to net cash generated from operating activities:
Share-based compensation	2,970	427	3,851	288,763
Depreciation and amortization	37,223	5,347	25,778	8,109
Loss on disposal of property and equipment	1,824	262		120
Loss/(gain) from equity method investments	136	20	(1,710)	4,890
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(39,769)	(5,712)	(92,291)	(30,222)
Deferred costs	(121,668)	(17,476)	(229,007)	(73,032)
Right-of-use asset	(38,805)	(5,574)
Deferred tax assets	(85,513)	(12,283)
Other non-current assets	3,446	495	(4,286)	(7,480)
Accrued expenses and other current liabilities	25,216	3,622	214,697	164,245
Deferred revenue	(57,255)	(8,224)	1,175,597	1,382,859
Lease liability	49,253	7,075
Deferred tax liabilities	87,954	12,634
Other non-current liabilities	(3,394)	(488)	14,864
Net cash generated from/(used in) operating activities	(533,547)	(76,638)	180,543	819,538
CASH FLOWS FROM INVESTING ACTIVITIES
Payment for equity method investments	(10,153)	(1,458)	(25,000)	(8,190)
Purchase of short-term investments	(2,108,820)	(302,913)	(4,352,103)	(2,139,097)
Proceeds from maturity of short-term investments	2,905,788	417,390	3,708,810	1,931,027
Acquisition of property and equipment	(24,756)	(3,556)	(517,763)	(398,190)
Acquisition of intangible assets	(780)	(112)	(665)	(746)
Consideration paid for a business acquisition, net of cash received				(699)
Proceeds from disposal of property and equipment	652	94
Loan to employees	(33,085)	(4,752)
Repayment of loan to employees	700	101
Net cash (used in) / generated from investing activities	729,546	104,794	(1,186,721)	(615,895)
CASH FLOWS FROM FINANCING ACTIVITIES
Amounts due from related parties			253,672	7,944
Capital contribution from Series B and B+ convertible redeemable preferred shareholders				732,709
Capital contribution from a noncontrolling shareholder				200
Capital withdrew from Series A convertible redeemable preferred shareholders				(285,078)
Capital withdrew from equity shareholders				(30,000)
Repurchase of equity from shareholders				(41,303)
Cash dividend to a Series A convertible redeemable preferred shareholder				(43,000)
Proceeds from initial public offering, net of issuance cost of 80,128			1,109,517
Payment for share repurchase	(31,650)	(4,546)	(33,971)
Proceeds from bank loans			260,000
Repayment of bank loans	(32,500)	(4,668)	(1,875)
Net cash generated from / (used in) financing activities	(64,150)	(9,214)	1,587,343	341,472
Effect of exchange rate changes	21,567	3,095	108,186	(8,759)
Net increase in cash and cash equivalents	153,416	22,037	689,351	536,356
Cash and cash equivalents at beginning of the year	1,248,810	179,380	559,459	23,103
Cash and cash equivalents at end of the year	1,402,226	201,417	1,248,810	559,459
Supplemental schedule of non-cash investing activities:
Payables for leasehold improvement and intangible assets	6,818	979	7,194	2,180
Payables to acquire buildings	61,540	8,840	61,540	¥ 240,390
Supplemental disclosure of cash flow information:
Interest paid	¥ 15,316	$ 2,200	¥ 1,099

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASHFLOWS (Parenthetical) - CNY (¥) ¥ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Statement Of Cash Flows [Abstract]
Stock issuance costs	¥ 80,128	¥ 80,128

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. ORGANIZATION AND BASIS OF PRESENTATION Sunlands Technology Group (the “Company” or “Sunlands Technology”) was incorporated under the laws of the Cayman Islands on September 18, 2015. The Company, its subsidiaries, its consolidated variable interest entities (“VIEs”) and VIEs’ subsidiaries (collectively the “Group”) are primarily engaged in providing online education service in the People’s Republic of China (“PRC” ). History of the Group In July 2011, Mr. Jianhong Yin (the “Founder”) established Sunland Education Co. Limited (the “Previous Cayman”). In March 2012, the Previous Cayman, through its 100% owned subsidiary, Sunland Education Technology HK Limited, established Beijing Shangzhi Jiaye Education Technology Co., Ltd. (the “Previous WFOE”). PRC laws and regulations currently require any foreign entity that invests in the education business in China to be an educational institution with relevant experience in providing education services outside China. To comply with the PRC laws and regulations, the Founder, Previous WFOE and Beijing Shangde Jiaxun Education Technology Co., Ltd. (“Shangde Jiaxun” or the “Previous VIE”), which was established by the Founder in July 2008, entered into a series of contractual arrangements in December 2013 (the “Previous VIE arrangement”). As a result of these contractual arrangements, the Previous Cayman believed that these contractual arrangements would enable itself to (1) have power to direct the activities that most significantly affects the economic performance of the Previous VIE, and (2) receive the economic benefits of the VIE that could be significant to the Previous VIE. Accordingly, the Previous Cayman was considered the primary beneficiary of the Previous VIE and was able to consolidate the Previous VIE and its subsidiaries. In June 2014, the Group determined to cease the offline, classroom-based education service and transform its business model to online education service. During 2015 and 2016, in order to execute the business shift and prepare for an initial public offering (“IPO”) in the PRC, the Group terminated the Previous VIE arrangement and started to conduct the online education service through Beijing Shangde Online Education Technology Co., Ltd. (the “2016 Reorganization”). Beijing Sunlands was set up by Shangde Jiaxun in September 2013 as a limited liability company in the PRC. In August 2017, the Group decided to pursue the IPO in the capital market overseas. To accommodate the aforementioned restrictions, the Group identified the Company as the prospective listing entity and entered into a series of contractual arrangements among the Company’s shareholders, its subsidiaries, the Founder, the Chief Executive Officer (the “CEO”) of the Group, Beijing Sunlands and the shareholders of Beijing Sunlands (the “2017 Reorganization”). 2016 Reorganization During 2015 and 2016, in part of the IPO plan in the PRC, the Group undertook a series of steps, mainly to dissolve the VIE structure, which includes: • During 2015, the Previous WFOE terminated the Previous VIE arrangement through which RMB49,359 was recognized as an effect of such reorganization in the Group’s consolidated statements of changes in shareholders’ deficit. Meanwhile, Shangde Jiaxun, the Previous VIE, transferred its equity interests in Beijing Sunlands to the Founder and the CEO. • From March to July 2016, based on the VIE termination agreement entered into by the shareholders of the Previous WFOE, Beijing Sunlands acquired 100% equity interests of the Previous WFOE at a cash consideration of RMB293,644. Such cash consideration was used by the Previous Cayman to repurchase the equity interests held by the third party investors of the Previous Cayman. • Subsequent to the repurchase, the shareholders of the Previous Cayman made capital contributions to Beijing Sunlands. After that, the shareholders of the Previous Cayman became the shareholders of Beijing Sunlands. 1. ORGANIZATION AND BASIS OF PRESENTATION - continued 2016 Reorganization- continued As the Previous Cayman, Previous WFOE and Beijing Sunlands were all under common control of the Founder, the above series of steps to reorganize the Group during 2015 and 2016 were accounted for in a manner similar to a pooling of interest with assets and liabilities and were all reflected at their historical amounts in the Group’s consolidated financial statements. 2017 Reorganization In August 2017, the Group decided to pursue the IPO in the capital market overseas. Accordingly, the Group undertook a series of steps, mainly to establish the VIE structure, which includes: • In August 2017, the Company, through its wholly-owned subsidiary, Sunlands Online Education HK Limited (formerly known as Studyvip Online Education HK Limited) (“Sunlands HK”), established Wuhan Studyvip Online Education Co., Ltd. (“Wuhan Zhibo” or the “New WFOE”). • In August 2017, the New WFOE entered into a series of contractual agreements with Beijing Sunlands (the “New VIE”), its subsidiaries and the shareholders of Beijing Sunlands (the “New VIE arrangements”). The Group believes that these contractual arrangements would enable the Company to (1) have power to direct the activities that most significantly affect the economic performance of the New VIE, and (2) receive the economic benefits of the VIE that could be significant to the New VIE. Accordingly, the Company is considered the primary beneficiary of the New VIE and is able to consolidate the New VIE and its subsidiaries. As the Company, New WFOE and New VIE were all under common control of the Founder, the above series of steps to reorganize the Group during 2017 were accounted for in a manner similar to a pooling of interest with assets and liabilities at their historical amounts in the Group’s consolidated financial statements. As such, the Group’s consolidated financial statements were prepared as if the current corporate structure had been in existence for all periods presented. In March 2018, the Founder and the CEO set up a new limited company, Tianjin Shangde Online Education Technology Co., Ltd. (“Tianjin Shangde”) to operate online education services. Subsequently, in May 2018, Tianjin Studyvip Education Co., Limited (“Tianjin Sunlands"), a wholly-owned subsidiary of the Group, entered into a series of contractual arrangements with Tianjin Shangde, and the shareholders of Tianjin Shangde, through which the Company obtained effective control over, and became the primary beneficiary of, Tianjin Shangde. 1. ORGANIZATION AND BASIS OF PRESENTATION - continued As of December 31, 2019, details of the Company’s subsidiaries, its VIEs and VIEs’ subsidiaries were as follows: Name (1) Date of establishment/ acquisition Place of establishment Percentage of direct or indirect economic ownership Principal activities Subsidiaries: Sunlands HK October 6, 2015 HongKong 100% Investment holding Wuhan Zhibo August 2, 2017 PRC 100% Provision of technical consultation and services Tianjin Sunlands July 31, 2017 PRC 100% Provision of technical consultation and services Wuhan Shangde Online Education Technology Co., Ltd. June 25, 2019 PRC 100% Provision of education services Chengdu Xinketang Cultural Communication Co., Ltd. November 4, 2019 PRC 100% Sales of educational materials and books Variable interest entities ("VIEs"): Beijing Sunlands September 27, 2013 PRC N/A* Investment holding and provision of education services Tianjin Shangde March 21, 2018 PRC N/A* Provision of education services VIEs’ subsidiaries: Beijing Shangzhi Jiaye Education Technology Co., Ltd. March 13, 2012 PRC 100% Provision of education services Beijing Shangren Chongye Education Technology Co., Ltd. September 27, 2013 PRC 100% Provision of education services Guangdong Shangde Online Education Technology Co., Ltd. October 15, 2013 PRC 100% Provision of education services Guangzhou Youhe Self-study Training School May 19, 2015 PRC 100% Provision of education services Beijing Heikuaima Education Technology Co., Ltd. (2) March 3, 2016 PRC 100% Provision of education services Shanghai Shangchi Education Technology Co., Ltd. December 22, 2016 PRC 90% Provision of education services Shanghai Shangchi Institute September 1, 2017 PRC 100% Provision of education services Guangzhou Shangzhi Side Education Technology Co., Ltd. September 28, 2017 PRC 100% Provision of education services * These entities are controlled by the Company pursuant to the contractual agreements disclosed below. (1) The English names are for identification purpose only. (2) The entity changed its legal name from Beijing Bainiao Education Technology Co., Ltd. to Beijing Heikuaima Education Technology Co., Ltd. in July 2019. 1. ORGANIZATION AND BASIS OF PRESENTATION - continued The VIE arrangements There are some uncertainties as to whether applicable PRC laws and regulations prohibit foreign investors from providing telecommunications value-added services in the PRC. As a Cayman Islands corporation, the Company is deemed a foreign legal person under PRC laws. Accordingly, the Company’s wholly owned subsidiaries in the PRC, as foreign invested companies, may be deemed to be telecommunications value-added services providers in the PRC. To comply with these foreign ownership restrictions, the Company operates substantially all of its online education services through its VIEs, Beijing Sunlands and Tianjin Shangde, and their subsidiaries, in the PRC. Through the below contractual agreements, Wuhan Zhibo and Tianjin Sunlands have (1) the power to direct the activities of the VIEs and their subsidiaries that most significantly affect their economic performance and (2) the right to receive substantially all the benefits from the VIEs and their subsidiaries. They are therefore considered the primary beneficiaries of the VIEs and their subsidiaries, and accordingly, the results of operations, assets and liabilities of the VIEs and their subsidiaries are consolidated in the Company's financial statements . • Agreements that transfer economic benefits to the Company Exclusive Technical Consultation and Service Agreement Under the exclusive technical consultation and service agreement among Wuhan Zhibo, and Beijing Sunlands and its subsidiaries, Wuhan Zhibo has the exclusive right to provide, among other things, technical consultation and services to Beijing Sunlands and Beijing Sunlands Subsidiaries, and Beijing Sunlands and Beijing Sunlands Subsidiaries agree to accept all the consultation and services provided by Wuhan Zhibo. Without Wuhan Zhibo’s prior written consent, Beijing Sunlands and Beijing Sunlands Subsidiaries are prohibited from engaging any third party to provide any services contemplated by this agreement. In addition, Wuhan Zhibo has exclusive and proprietary ownership, rights and interests in any and all intellectual properties arising out of or created during the performance of this agreement. Beijing Sunlands and Beijing Sunlands Subsidiaries agree to pay a quarterly service fee to Wuhan Zhibo at an aggregate amount of a certain percentage ranging from 10% to 100% of Beijing Sunlands and Beijing Sunlands Subsidiaries’ monthly revenue. Unless terminated by Wuhan Zhibo, this agreement will remain effective until the dissolution of Beijing Sunlands and Beijing Sunlands Subsidiaries. Without Wuhan Zhibo’s prior written consent, Beijing Sunlands and Beijing Sunlands Subsidiaries do not have the right to terminate this exclusive technical consultation and service agreement. Tianjin Sunlands, Tianjin Shangde and its subsidiaries have entered into an Exclusive Technical Consultation and Service Agreement on May 21, 2018, the terms of which are substantially the same as the agreement of Beijing Sunlands summarized above. Business Operation Agreement Under the business operation agreement each of Beijing Sunlands, Beijing Sunlands Subsidiaries and the shareholders of Beijing Sunlands confirmed and agreed that, without Wuhan Zhibo’s prior written consent, it shall not make any transaction that has a material adverse effect on the assets, business, personnel, obligations, rights or operations of Beijing Sunlands and Beijing Sunlands Subsidiaries, including but not limited to sale or purchase of any assets or rights exceeding RMB50, incurrence of any encumbrance on any of its assets, including intellectual property rights, in favor of a third party, amendment of its articles of association or business scope, or change of its normal operation procedures. Beijing Sunlands, Beijing Sunlands Subsidiaries and the shareholders of Beijing Sunlands shall accept and execute opinions and instructions of Wuhan Zhibo in connection with the employee engagement and dismissal, daily operations and financial management systems. The shareholders of Beijing Sunlands shall elect or appoint the candidates recommended by Wuhan Zhibo as Beijing Sunlands’ directors and supervisors, and procure the appointment of Beijing Sunlands’ chairman of the board and senior management pursuant to Wuhan Zhibo’s designation. The agreement also provides that if any of the agreements among Wuhan Zhibo, Beijing Sunlands and the Beijing Sunlands Subsidiaries is terminated, Wuhan Zhibo is entitled to terminate all of the other agreements among itself, Beijing Sunlands and Beijing Sunlands Subsidiaries. This agreement will remain binding until dissolution of Beijing Sunlands and all the Beijing Sunlands Subsidiaries. Tianjin Sunlands, Tianjin Shangde and its subsidiaries, and the shareholders of Tianjin Shangde have entered into a Business Operation Agreement on May 21, 2018, the terms of which are substantially the same as the agreement of Beijing Sunlands summarized above. 1. ORGANIZATION AND BASIS OF PRESENTATION - continued The VIE arrangements – continued • Agreements that transfer economic benefits to the Company – continued Equity Interest Pledge Agreement Pursuant to the equity interest pledge agreement among Wuhan Zhibo, the shareholders of Beijing Sunlands and its subsidiaries, the shareholders of Beijing Sunlands pledged all of their equity interests in Beijing Sunlands to Wuhan Zhibo as security for performance of the obligations of Beijing Sunlands and its shareholders under the exclusive technical consultation and service agreements, the option agreement and the business operation agreement. The shareholders of Beijing Sunlands shall instruct Beijing Sunlands not to distribute any dividends and shall not approve any profit distribution plan. If any of the specified events of default occurs, Wuhan Zhibo may exercise the right to enforce the pledges after giving a notice of default to the shareholders of Beijing Sunlands. Wuhan Zhibo may assign any and all of its rights and obligations under equity interest pledge agreement to its designee(s) at any time. The equity interest pledge agreement is binding on the shareholders of Beijing Sunlands and their successors and shall be valid with respect to the shareholders of Beijing Sunlands and each of its successors. Tianjin Sunlands and the shareholders of Tianjin Shangde and its subsidiaries have entered into an Equity Interest Pledge Agreement on May 21, 2018, the terms of which are substantially the same as the agreement of Wuhan Zhibo summarized above. • Agreements that provide the Company effective control over Beijing Sunlands and Tianjin Shangde Option Agreement Pursuant to the option agreement among Wuhan Zhibo, the shareholders of Beijing Sunlands and Beijing Sunlands, each of the shareholders irrevocably granted Wuhan Zhibo a right to purchase or designate a third party to purchase, equity interests in Beijing Sunlands then held by each shareholder at once or at multiple times at any time in part or in whole at Wuhan Zhibo’s sole and absolute discretion to the extent permitted by PRC law. The shareholders of Beijing Sunlands shall promptly surrender all considerations they received from the exercise of the options to Wuhan Zhibo or the designated third party free of charge. Without Wuhan Zhibo’s prior written consent, the shareholders of Beijing Sunlands shall not, individually or collectively, make or procure Beijing Sunlands to make any transaction or conduct that has a material adverse effect on the assets, liabilities, operations, equity and other legal rights of Beijing Sunlands. Without Wuhan Zhibo’s prior written consent, Beijing Sunlands shall not enter into any contract exceeding RMB50, except the contracts in the ordinary course of the business. Beijing Sunlands shall not be dissolved or liquidated without prior written consent by Wuhan Zhibo. The shareholders of Beijing Sunlands waive their rights of pre-emption in regard to the transfer of equity interest by any other shareholder of Beijing Sunlands to Wuhan Zhibo as instructed. Tianjin Sunlands, the shareholders of Tianjin Shangde and Tianjin Shangde have entered into an Option Agreement on May 21, 2018, the terms of which are substantially the same as the agreement of Wuhan Zhibo summarized above. Powers of Attorney Pursuant to the powers of attorney executed by the shareholders of Beijing Sunlands, the shareholders of Beijing Sunlands each irrevocably authorized Wuhan Zhibo to act on their respective behalf as exclusive agent and attorney with respect to all rights of shareholders concerning all equity interests held by each of them in Beijing Sunlands, including but not limited to propose to convene shareholder meetings, accept any notice with respect to the convening and proceeding of the shareholder meeting, attend shareholder meetings, sign the shareholders resolutions on behalf of, exercise all the shareholder’s rights and Beijing Sunlands’ articles of association (including but not limited to voting rights and the sale, transfer, pledge, or dispose of all equity interests held in part or in whole), and designate and appoint on their respective behalf the president, directors, supervisors, CEO, chief financial officer and other senior management members of Beijing Sunlands. 1. ORGANIZATION AND BASIS OF PRESENTATION - continued The VIE arrangements – continued • Agreements that provide the Company effective control over Beijing Sunlands and Tianjin Shangde – continued Powers of Attorney – continued The shareholders of Tianjin Shangde each irrevocably authorized Tianjin Sunlands to act on their respective behalf as executive agent and attorney with respect to all rights of shareholders pursuant the power of attorney executed on May 21, 2018. Spousal Consent Letters Pursuant to the spousal consent letters executed by the spouses of the general partners of entities as the shareholders of Beijing Sunlands and Tianjin Shangde, the signing spouse confirmed and agreed that the equity interests of Beijing Sunlands and Tianjin Shangde are the own property of their spouses and shall not constitute the jointly possessed property of the couples. The spouses also irrevocably waived any potential right or interest that may be granted by operation of applicable law in connection with the equity interests of Beijing Sunlands and Tianjin Shangde held by their spouse s. As a result of the contractual arrangements above, Wuhan Zhibo and Tianjin Sunlands bear the economic risks and receive the economic benefits of the VIEs and are the primary beneficiary of the VIEs. Therefore, the Company has consolidated the financial results of the VIEs and their subsidiaries in its consolidated financial statement s. Risks in relation to VIE structure The Company believes that the contractual arrangements with Beijing Sunlands, Tianjin Shangde and their shareholders are in compliance with existing PRC laws and regulations and are legally enforceable. However, the contractual arrangements are subject to risks and uncertainties, including : • Beijing Sunlands, Tianjin Shangde and their shareholders may have or develop interests that conflict with the Group’s interests, which may lead them to pursue opportunities in violation of the aforementioned contractual agreements. If the Group cannot resolve any conflicts of interest or disputes between the Group and the shareholders of Beijing Sunlands and Tianjin Shangde, the Group would have to rely on legal proceedings, which could result in disruption of its business, and there is substantial uncertainty as to the outcome of any such legal proceedings . • Beijing Sunlands, Tianjin Shangde and their shareholders could fail to obtain the proper operating licenses or fail to comply with other regulatory requirements. As a result, the PRC government could impose fines, new requirements or other penalties on the VIEs or the Group, mandate a change in ownership structure or operations for the VIEs or the Group, restrict the VIEs or the Group’s use of financing sources or otherwise restrict the VIEs or the Group’s ability to conduct business . • The PRC government may declare the aforementioned contractual arrangements invalid. They may modify the relevant regulations, have a different interpretation of such regulations, or otherwise determine that the Group or the VIEs have failed to comply with the legal obligations required to effectuate such contractual arrangements. • If the legal structure and contractual arrangements were found to be in violation of PRC laws and regulations, the PRC government may restrict or prohibit the Group’s business and operations in China. The Group’s ability to conduct its business may be negatively affected if the PRC government were to carry out any of the aforementioned actions. As a result, the Group may not be able to consolidate Beijing Sunlands, Tianjin Shangde and their subsidiaries in the consolidated financial statements as the Group may lose the ability to exert effective control over Beijing Sunlands, Tianjin Shangde and their shareholders, and the Group may lose the ability to receive economic benefits from Beijing Sunlands and Tianjin Shangde . 1. ORGANIZATION AND BASIS OF PRESENTATION - continued The VIE arrangements - continued The following financial information of the VIEs and their subsidiaries as of December 31, 2018 and 2019 and for each of the three years in the period ended December 31, 2019 was included in the accompanying consolidated financial statements after elimination of intercompany transactions and balances within the subsidiaries, VIEs and their subsidiaries: As of December 31, 2018 2019 RMB RMB Cash and cash equivalents 80,371 69,539 Short-term investments 587,051 38,990 Prepaid expenses and other current assets 46,601 106,568 Total current assets 818,480 284,887 Right-of-use assets — 340,302 Total non-current assets 377,856 776,783 Total assets 1,196,336 1,061,670 Accrued expenses and other current liabilities 241,204 209,727 Deferred revenue, current 1,765,085 1,162,938 Lease liabilities, current — 22,659 Total current liabilities 2,006,289 1,395,324 Deferred revenue, non-current 1,520,940 1,096,482 Lease liabilities, non-current — 358,467 Total liabilities 3,527,364 2,854,823 Years ended December 31, 2017 2018 2019 RMB RMB RMB Net revenues 970,162 1,973,985 2,049,461 Net (loss)/income (606,946 ) 393,063 590,728 Net cash generated from/(used in) operating activities 845,616 1,448,005 (480,084 ) Net cash (used in)/generated from investing activities (375,802 ) (315,198 ) 522,104 Net cash (used in)/generated from financing activities (391,237 ) 8,018 — There are no consolidated VIEs’ assets that are collateral for the VIEs’ obligations and which can only be used to settle the VIEs’ obligations.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	2. SIGNIFICANT ACCOUNTING POLICIES Basis of presentation and use of estimates The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the balance sheet dates and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in the Group’s financial statements include, but are not limited to, consolidation of VIEs, valuation allowance for deferred tax assets, the variable consideration to be earned for certain online courses, useful lives of property and equipment, impairment of long-term assets and valuation of share-based compensation. Actual results could materially differ from those estimates. Principles of consolidation The consolidated financial statements include the financial statements of the Company and its subsidiaries, and VIEs and VIEs’ subsidiaries. All intercompany transactions and balances were eliminated upon consolidation. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Foreign currency translation and transactions The Group’s reporting currency is Renminbi (“RMB”). The functional currency of the subsidiaries incorporated outside the mainland China is United States dollar (“US dollar” or “US$”). The functional currency of all the other subsidiaries and the VIEs and VIEs’ subsidiaries is RMB. Monetary assets and liabilities denominated in currencies other than the applicable functional currencies are translated into the functional currencies at the prevailing rates of exchange at the balance sheet date. Nonmonetary assets and liabilities are remeasured into the applicable functional currencies at historical exchange rates. Revenues and expenses are translated using the average rate of exchange in effect during the reporting period. Translation adjustments are reported and shown as a separate component of other comprehensive loss in the consolidated statements of changes in shareholders’ deficit and the consolidated statements of comprehensive loss. Transactions in currencies other than the functional currencies during the year are converted into the applicable functional currencies at the applicable rates of exchange prevailing at the dates of the transactions. Transaction gains and losses are recorded in the consolidated statements of operations. Convenience Translation The Group’s business is primarily conducted in China and all of the revenues are denominated in RMB. However, periodic reports made to shareholders will include current period amounts translated into US dollars using the then current exchange rates, for the convenience of the readers. Translations of balances in the consolidated balance sheets, and the related consolidated statements of operations, shareholders’ deficit and cash flows from RMB into US dollars as of and for the year ended December 31, 2019 are solely for the convenience of the readers and were calculated at the rate of US$1.00= RMB6 Cash and cash equivalents Cash and cash equivalents comprise cash at banks and on hand and term deposits, which have original maturities of three months or less when purchased and are subject to an insignificant risk of changes in value. The carrying value of cash equivalents approximates market value. Short-term investments Short-term investments consist of financial products with unsecured principal purchased from commercial banks and financial institutions which have original maturities of less than one year. The carrying amount of these short-term investments approximates their fair values due to the short-term maturities of these investments and are carried at amortized cost. The Group reviews its short-term investments for impairment whenever an event or circumstance indicates that impairment has occurred. The Group considers available quantitative and qualitative evidence in evaluating the potential impairment of its short-term investments. An impairment charge is recorded in the consolidated statements of operations if the carrying amount of an investment exceeds the investment’s fair value. Long-term investments Investee companies over which the Group has the ability to exercise significant influence, but does not have a controlling interest through investment in common shares or in-substance common shares, are accounted for using the equity method. Significant influence is generally considered to exist when the Group has an ownership interest in the voting stock of the investee between 20% and 50%, and other factors, such as representation on the investee’s board of directors, voting rights and the impact of commercial arrangements, are also considered in determining whether the equity method of accounting is appropriate. For certain investments in limited partnerships, where the Group holds less than a 20% equity or voting interest, the Group may also have significant influence. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Long-term investments - continued Under the equity method of accounting, the Group initially records its investment at cost and subsequently recognizes the Group’s proportionate share of each equity investee’s net income or loss after the date of investment into earnings and adjusts the investment carrying amount accordingly. The Group reviews its equity method investments for impairment whenever an event or circumstance indicates that any other-than-temporary impairment has occurred. The Group considers available quantitative and qualitative evidence in evaluating potential impairment of its equity method investments. An impairment charge is recorded when the carrying amount of the investment exceeds its fair value and this condition is determined to be other-than-temporary. Fair value Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Group considers the principal or most advantageous market in which it would transact and it considers assumptions that market participants would use when pricing the asset or liability. Authoritative literature provides a fair value hierarchy which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The level in the hierarchy within which the fair value measurement in its entirety falls is based upon the lowest level of input that is significant to the fair value measurement as follows: Level 1 Level 1 applies to assets or liabilities for which there are quoted prices in active markets for identical assets or liabilities. Level 2 Level 2 applies to assets or liabilities for which there are inputs other than quoted prices included within Level 1 that are observable for the asset or liability such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical assets or liabilities in markets with insufficient volume or infrequent transactions (less active markets); or model-derived valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data. Level 3 Level 3 applies to assets or liabilities for which there are unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of the assets or liabilities. Financial instruments The Group’s financial instruments consist primarily of cash and cash equivalents, short-term investments, other current liabilities and long-term debt. The carrying amount of long-term debt approximates fair value as its interest rates are at the same level of current market yield for comparable debts. The carrying amounts of other financial instruments approximate their fair values due to short-term maturities. Property and equipment, net Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the assets, as follows: Category Estimated useful life Buildings 36-37 years Leasehold and buildings improvements Shorter of lease term or expected useful life Electronic and office equipment 3-5 years 2. SIGNIFICANT ACCOUNTING POLICIES - continued Property and equipment, net - continued Repair and maintenance costs are charged to expense as incurred, whereas the cost of renewals and betterment that extends the useful lives of property and equipment are capitalized as additions to the related assets. Retirements, sales and disposals of assets are recorded by removing the cost and accumulated depreciation from the asset and accumulated depreciation accounts with any resulting gain or loss reflected in the consolidated statements of operations. Intangible assets, net Intangible assets are amortized using the straight-line basis over the estimated useful lives as follows: Category Estimated useful life Computer software 3 years License 5 years Impairment of long-lived assets The Group reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may no longer be recoverable. When these events occur, the Group measures impairment by comparing the carrying value of the long-lived assets to the estimated undiscounted future cash flows expected to result from the use of the assets and their eventual disposition. If the sum of the expected undiscounted cash flow is less than the carrying amount of the assets, the Group would recognize an impairment loss based on the fair value of the assets. The Group did not record any impairment losses on its long-lived assets during the years ended December 31, 2017, 2018 and 2019. Revenue recognition The Group early adopted the accounting standard Revenue from Contracts with Customers (ASC 606) as of January 1, 2017 using the full retrospective method which requires the Group to present its financial statements for all periods as if ASC 606 had been applied to all prior periods. The Group did not apply practical expedients as provided under ASC 606. The Group follows five steps for its revenue recognition under ASC 606: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Group’s revenue is reported net of discount, business tax, value added tax and related surcharges. The primary sources of the Group’s revenues are as follows: Online education services For online education services, the Group provides an integrated online education service package to students, including online live streaming audio-video interactive course content, recorded previous live audio-video course content, quiz banks, online chat rooms, and educational contents. The services and goods provided in the package are highly interdependent and interrelated in the context of the contract and are only considered accessory services to the online live streaming and recorded courses which are not distinct and are not sold standalone. Therefore, the Group's integrated online education services package is accounted for as a single performance obligation. The weighted average service period for degree- or diploma-oriented post-secondary courses and professional certification preparation and professional skills courses was 32 months and 19 months, respectively, for the year ended December 31, 2019. The transaction price of the integrated online education service package is determined by the contract amount net of any discounts. Students are offered a full, unconditional refund within 24 hours upon enrollment. Prior to June 2019, undelivered courses was eligible for refund, excluding registration fees, within 7 days after enrollment. For course contracts entered after June 2019, undelivered courses is eligible for refund during the entire service period, excluding registration fees. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Revenue recognition – continued Online education services – continued Revenues for online education services are recognized on a straight line basis over the service period from the registration day to the day on which the service period ends. For certain online courses, the Group also provided students the right to apply for refund for the delivered courses if certain pre-agreed conditions are achieved. The Group estimated the variable consideration to be earned to the extent it was probable that a significant reversal of cumulative revenue recognized would not occur when the uncertainty associated with the variable consideration was resolved and recognized revenue over time from the registration day to the day on which the service period ended on a straight line basis. The Group's estimates of variable consideration and determination of whether to include estimated amounts in the transaction price were based largely on an assessment of the Group's anticipated performance and all information (historical, current and forecasted) that was reasonably available. For certain online courses, the service period includes a regular period plus an extended period. The Group offers students an extended service period after the regular period if certain pre-agreed conditions are met. Based on historical passing rates, and forecasted passing rates due to continuous improvement of service quality, the Group applies and categorizes the students by portfolio (1) eligible to extended period and (2) not eligible to extended period and estimates the portion of each portfolio. The Group recognizes the revenue on each portfolio over time from the registration day to the day on which the service is expected to end on a straight line basis. For certain online courses, the Group offers a bundled service including an integrated online education service package with insurance coverage for tuition refund. If certain refund conditions are met, students could claim the insurance equal to full or partial amount of the service fee. The Group identifies that the integrated online education service package and the insurance service are two separate performance obligations as students benefit from each service on its own and they are separately identifiable in the contract. The Group records revenue generated from online education services with insurance coverage on a gross basis as the Group is acting as the principal to fulfill all obligation and control all the services transferred to the students. The Group's deferred costs represent the unamortized incremental sales commission relating to obtaining of customers contract, and the contract liability primarily consists of deferred revenue. Student Financing The Group offers an installment payment option to students, under which the students obtain loans, from accredited credit sources (“Loan Companies”) for the purpose of satisfying the student’s tuition payment due. The borrowing student is obligated to repay the loan principal in installments over periods ranging from 3 months to 18 months to the Loan Companies, while the Group agrees with the Loan Companies to bear the student’s interest expense and service fees. The Loan Companies remit the tuition to the Group for students to complete the registration. The interest expense and service fees are recorded as a reduction of the transaction price. Commission revenue The Group earns commission revenue by providing referral services to third party education institutions. Commission revenue is recognized when the referred students registered at the third party education institutions and the tuition fees are paid, by when the performance obligation is satisfied. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Revenue recognition – continued Deferred Revenue Revenues related to the Group’s online courses are recognized over time. Deferred revenue consists of tuition fees received from students for which services have not yet been provided to students. Value added taxes (“VAT”) The Group's services are subject to VAT at the rate of 6% for general-VAT-payer entities in accordance with tax rule, except that certain subsidiaries were subject to a simple VAT collection method at a rate of 3% before June 2019. Cost of revenue Cost of revenues consist of expenditures incurred in the generation of the Group’s revenue, includes but not limited to salaries and benefits paid to teachers, related rental expenses, server management costs, bandwidth costs, payment processing costs, insurance cost, depreciations for property and equipment and amortizations for intangible assets. Product development expenses Product development expenses primarily consist of (i) salaries and benefits for innovation and development of course content, product and technology development personnel, and (ii) office rental, general expenses and depreciation and amortization expenses associated with the product development activities. The Group’s product development activities primarily consist of the development and enhancement of the Group’s educational content, applications and platforms. The Group has expensed all product development expenses when incurred. Sales commission The incremental sales commission relating to obtaining of the customer contract and expected to be recovered is accounted for as an incremental cost of obtaining a contract and is capitalized as deferred costs when incurred. The capitalized cost is amortized in the same manner as the revenue recognized and is included in “sales and marketing expenses” in the consolidated statements of operations. Other sales commission incurred regardless of whether the contract was obtained is recognized as an expense when incurred. Advertising expenditure Advertising expenditure, mainly includes search engine marketing and mobile marketing expenses, is expensed when incurred and is included in sales and marketing expenses in the consolidated statements of operations. Advertising expenses were RMB499,294, RMB983,012 and RMB937,145 for the years ended December 31, 2017, 2018 and 2019, respectively. Sales and marketing expenses Sales and marketing expenses primarily consist of (i) salaries and benefits for sales and marketing personnel, (ii) search engine marketing and mobile marketing expenses and other advertising expenses, (iii) office rental, general expenses and depreciation and amortization expenses associated with the sales and marketing activities. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Leases The Group leases administrative office spaces and enrollment centers in different cities in the PRC under operating leases. The Group determines whether an arrangement constitutes a lease at inception. The Group has lease agreements with lease and non-lease components, which are generally accounted for separately. The allocation of the consideration between the lease and the non-lease components is based on the relative stand-alone prices of lease components included in the lease contracts. Operating lease right-of-use assets and liabilities are recognized at lease commencement date based on the present value of remaining lease payments over the lease terms. The Group uses the implicit rate when readily determinable, or its incremental borrowing rate based on the information available, at the commencement date in determining the present value of lease payments. Certain leases include renewal options and/or termination options. Renewal options are included in the lease term if the Group is reasonably certain to exercise those options while options to terminate the lease are only included in the lease term if the Group is reasonably certain not to exercise those options. Lease expense is recorded on a straight-line basis over the lease term. For short-term leases, the Group records operating lease expense in its consolidated statements of operations on a straight-line basis over the lease term. Government subsidies For the government subsidies not subject to further performance obligations or future returns, the Group records the amounts as other income when received from local government authority. Whereas for the government subsidies with future performance obligations, the Group recognizes those as liabilities when received until the performances obligations have been met at which time, those are recognized as other income. Government subsidies received and recorded as other income amounted to RMB3,223, RMB28,688 and RMB14,692 for the years ended December 31, 2017, 2018 and 2019, respectively. Income taxes Current income taxes are provided for in accordance with the laws of the relevant tax authorities. Deferred income taxes are recognized when temporary differences exist between the tax bases of assets and liabilities and their reported amounts in the financial statements. Net operating loss carry forwards and credits are applied using enacted statutory tax rates applicable to future years. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more-likely-than-not that a portion of or all of the deferred tax assets will not be realized. The impact of an uncertain income tax position is recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant tax authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Interest and penalties on income taxes will be classified as a component of the provisions for income taxes. Comprehensive loss Comprehensive loss includes net loss and foreign currency translation adjustments and is reported in the consolidated statements of comprehensive loss. The Group presents the components of net loss, the components of other comprehensive loss and total comprehensive loss in two separate but consecutive statements. Net loss per share Prior to IPO, basic net loss per share is computed by dividing net loss attributable to ordinary shareholders of the Company by the weighted average number of ordinary shares outstanding during the year using the two-class method. The holders of the convertible redeemable preferred shares are entitled to share dividends on a pro rata basis, as if their shares had been converted into ordinary shares. Accordingly, the Company has used the two-class method in computing net loss per share. Under the two-class method, net loss is allocated on a pro rata basis to each class of ordinary shares and other participating securities based on their participating rights. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Net loss per share - continued After IPO, basic net loss per share is computed by dividing net loss attributable to ordinary shareholders of the Company by the weighted average number of common shares outstanding during the year. Diluted net loss per share reflects the potential dilution that could occur if securities or other contracts to issue common shares were exercised into common shares. To calculate the number of shares for diluted loss per share, the effect of the share options is computed using the treasury stock method. As the Company was loss making for the years ended December 31, 2017, 2018 and 2019, the effect of potential issuances of shares for the convertible redeemable preferred shares and share options would be anti-dilutive, and therefore basic and diluted losses per share are the same in those periods. Share-based compensation Share-based compensation with employees is measured based on the grant date fair value of the equity instrument. Share-based compensation expenses, net of forfeitures, are recognized over the requisite service period based on a straight-line basis with a corresponding impact reflected in additional paid-in capital. Share-based compensation awards which require the issuance of a variable number of shares to settle a fixed monetary amount are recorded as liabilities. Significant risks and uncertainties Foreign currency risk RMB is not a freely convertible currency. The State Administration for Foreign Exchange, under the authority of the People’s Bank of China, controls the conversion of RMB into foreign currencies. The value of RMB is subject to changes in central government policies and to international economic and political developments affecting supply and demand in the China Foreign Exchange Trading System market. The cash and cash equivalents of the Group included aggregate amounts of RMB157,103 and RMB259,612, which were denominated in RMB at December 31, 2018 and 2019, representing 12.6% and 18.5% of the cash and cash equivalents at December 31, 2018 and 2019, respectively. Concentration of credit risk Financial instrument that potentially expose the Group to significant concentration of credit risk primarily consist of cash and cash equivalents, short-term investments and prepaid expenses and other current assets. The Group places its cash and cash equivalents and short-term investments in financial institutions with high credit ratings. There are no revenues from customers which individually represent greater than 10% of the total net revenues for any year of the three years period ended December 31, 2019. Newly adopted accounting pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842). The guidance supersedes existing guidance on accounting for leases with the main difference being that operating leases are to be recorded in the statement of financial position as right-of-use assets and lease liabilities, initially measured at the present value of the lease payments. For operating leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and liabilities. For public business entities, the guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application of the guidance is permitted. In July 2018, ASU 2016-02 was updated with ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides entities with relief from the costs of implementing certain aspects of the new leasing standard. Specifically, under the amendments in ASU 2018-11, (1) entities may elect not to recast the comparative periods presented when transitioning to ASC 842 and (2) lessors may elect not to separate lease and nonlease components when certain conditions are met. Before ASU 2018-11 was issued, transition to the new lease standard required application of the new guidance at the beginning of the earliest comparative period presented in the financial statements. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Newly adopted accounting pronouncements - continued The Group adopted Topic 842 on January 1, 2019 using the modified retrospective transition approach under ASU 2018-11, without adjusting comparative periods presented. The Group elected the practical expedient package to not reassess prior conclusions related to contracts containing leases, lease classification, and initial direct costs for any existing leases and the Group elected not to record on the balance sheets for leases with an initial term of twelve months or less. Upon adoption, the Group recognized right-of-use assets of RMB560.2 million and total lease liabilities (including current and non-current) of RMB607.2 million on the consolidated balance sheet as of January 1, 2019 for operating leases related to office space and enrollment centers. The adoption did not have a material impact on the Group's consolidated statements of operations or consolidated statements of cash flows, and the adoption of Topic 842 did not result in a cumulative-effect adjustment to retained earnings. Further information is disclosed in Note 16. Recently issued accounting pronouncements not yet adopted In June 2016, the FASB issued ASU 2016-13, "Financial Instruments-Credit Losses (Topic 326)", which requires entities to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early application will be permitted for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. In April 25, 2019, ASU 2016-13 was updated with ASU 2019-04, which clarifies certain aspects of accounting for credit losses, hedging activities and financial instruments and provides certain alternatives for the measurement of the allowance for credit losses on accrued interest receivable. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820)—Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this ASU improve the effectiveness of fair value measurement disclosures and modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements, including the consideration of costs and benefits. The amendments in this ASU are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities ("VIE"). The guidance was issued in response to stakeholders' observations that Topic 810, Consolidation, could be improved in the areas of applying the VIE guidance to private companies under common control and in considering indirect interests held through related parties under common control for determining whether fees paid to decision makers and service providers are variable interests. The new standard will become effective for the Group beginning January 1, 2020, with early adoption permitted, and must be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard.

Short-Term Investments

Short-Term Investments	12 Months Ended
	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Short-Term Investments	3 . SHORT-TERM INVESTMENTS Short-term investments consist of various financial products with unsecured principal from financial institutions in China at original maturity less than one year when purchased. While these financial products are not publicly traded, the Group estimated that their fair value approximated the costs considering their short-term maturities and high credit quality. As of December 31, 2018 2019 RMB RMB Short-term investments 1,028,564 217,640 No impairment loss was recognized for the three years ended December 31, 2017, 2018 and 2019.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	4 . PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following: As of December 31, 2018 2019 RMB RMB Prepaid and input VAT 58,234 120,376 Prepaid expenses (1) 10,820 21,896 Prepaid marketing expenses 23,756 16,192 Deposits (2) 4,595 8,929 Receivables from third-party payment platforms 3,886 4,367 Interest receivables 11,632 1,737 Staff advances 9,242 751 Others 2,743 6,633 Total 124,908 180,881 (1) Represented the prepaid expenses for telecommunications, network, online live steaming, advertising and student academic registration fee. ( 2 ) Represented rental deposits, deposits for search engine marketing activities and deposits for leasehold improvement of buildings which all being refundable within one year.

Deferred Costs

Deferred Costs	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Deferred Costs	5 . DEFERRED COSTS Deferred costs primarily consist of the incremental sales commission and service fee relating to obtaining of customers contract which is expected to be recovered and is capitalized pursuant to ASC340-40. The capitalized sales commission is amortized in the same manner the related revenue being recognized. The movements of deferred costs for the years ended December 31, 2018 and 2019 are as follows: As of December 31, 2018 2019 RMB RMB Beginning balances (current and non-current) 98,260 327,267 Additions 374,594 440,495 Amortizations (145,488 ) (318,693 ) Impairments (99 ) (134 ) Ending balances (current and non-current) 327,267 448,935 Deferred costs, current 180,657 243,447 Deferred costs, non-current 146,610 205,488

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Property and Equipment, Net	6 . PROPERTY AND EQUIPMENT, NET Property and equipment consisted of the following: As of December 31, 2018 2019 RMB RMB Leasehold and buildings improvements 91,265 106,377 Electronic and office equipment 29,936 35,049 Buildings (1) 480,271 480,271 Total cost 601,472 621,697 Less: Accumulated depreciation (41,961 ) (76,022 ) Property and equipment, net 559,511 545,675 (1) In 2017, the Group purchased two buildings in Wuhan (Building A and B) and one building in Guangzhou (Building C) with a total consideration of RMB480,271. RMB60,000 of the consideration was paid by a mortgage loan provided by a PRC bank in August 2018 (Note 12). Depreciation expenses were RMB7,333, RMB24,930 and RMB36,250 for the years ended December 31, 2017, 2018 and 2019, respectively.

Intangible Assets, Net

Intangible Assets, Net	12 Months Ended
	Dec. 31, 2019
Intangible Assets Net Excluding Goodwill [Abstract]
Intangible Assets, Net	7 . INTANGIBLE ASSETS, NET The balance of intangible assets consisted of the following: As of December 31, 2018 2019 RMB RMB Computer software 3,757 3,757 License — 780 Less: Accumulated amortization (2,388 ) (3,361 ) Intangible assets, net 1,369 1,176 Amortization expenses were RMB776, RMB 848 973 The intangible assets amortization expenses for each of the following fiscal years are as follows: Amortization RMB 2020 479 2021 255 2022 156 2023 156 2024 130 Total 1,176

Long-Term Investments

Long-Term Investments	12 Months Ended
	Dec. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Long-Term Investments	8 . LONG-TERM INVESTMENTS The Group made investments in three limited partnerships and accounts for these investments under the equity method because the Group has the ability to exercise significant influence but does not have control over the investees. The Group reviewed the investments for impairment whenever an event or circumstance indicates that an other-than-temporary impairment has occurred. The Group recorded its shares of loss at RMB4,890, gain at RMB1,710 and loss at RMB136 in these investments for the years ended December 31, 2017, 2018 and 2019, respectively. As of December 31, 2018 and 2019, no impairment loss was recorded in regard to these investments

Other Non-Current Assets

Other Non-Current Assets	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Other Non-Current Assets	9 . OTHER NON-CURRENT ASSETS Other non-current assets consisted of the following: As of December 31, 2018 2019 RMB RMB Prepayment to acquire a building (1) 404,725 404,725 Employee loans (2) — 32,385 Rental deposits (3) 12,772 9,326 Others 1,203 1,203 Total 418,700 447,639 (1) The amount represented the prepayment for a building (Building D) in Wuhan and the building remained under construction by the real estate developer as of December 31, 2019. RMB200,000 of the prepayment was made through a mortgage loan provided by a PRC bank in November 2018 (Note 12). (2) In 2019, the Group approved an employee benefit program under which eligible employees can apply for loans from the Group at prevailing interest rates. Upon maturity, the loans can be repaid by cash or the Company's ordinary shares held by those employees based on prevailing market price at the settlement date. (3) The amount represented office and enrollment centers’ rental deposits under the lease contracts, which are not refundable within one year.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	10 . ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES The components of accrued expenses and other liabilities are as follows: As of December 31, 2018 2019 RMB RMB Refund liability (1) 6,625 128,478 Salary and welfare payables 124,137 113,945 Accrued service fees (2) 94,789 69,932 Accrued marketing expenses 120,269 51,796 Accrued rental expenses 51,087 — Payables to educational institutions (3) 6,024 23,071 Other tax liabilities 29,872 15,263 Advanced deposits (4) 6,650 11,681 Payables for leasehold improvement and intangible assets 4,911 6,818 American Depositary Receipt commission - within one year 3,482 3,526 Payables for share repurchase 857 — Other payables 6,581 10,715 455,284 435,225 (1 ) Refund liability represented the estimated amounts of deferred revenue with contingency in cash refund. (2) The balance represented accrued expenses for outsourced service providers and other professional services. (3 ) The balance represented tuition fees collected from the students for their registrations with educational institutions. (4) Advanced deposits primarily included down payments paid by prospective students before contracts signing.

Revenues and Deferred Revenue

Revenues and Deferred Revenue	12 Months Ended
	Dec. 31, 2019
Disaggregation Of Revenue [Abstract]
Revenues and Deferred Revenue	11 . REVENUES AND DEFERRED REVENUE For the years ended December 31, 2017, 2018 and 2019, all of the Group’s revenues were generated in the PRC, and the disaggregated revenues by types were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Disaggregation of revenues Revenue by types: Gross revenues: Degree- or diploma-oriented post-secondary courses 822,832 1,814,178 2,021,990 Professional certification preparation and professional skills courses 145,840 161,366 155,370 Subtotal Online educational courses 968,672 1,975,544 2,177,360 Commissions 4,105 6,374 15,381 Others 1,901 587 8,100 Total revenues 974,678 1,982,505 2,200,841 Less: sales tax and surcharges (4,516 ) (8,520 ) (6,939 ) Total net revenues 970,162 1,973,985 2,193,902 The movements of the deferred revenue for the years ended December 31, 2018 and 2019 were as follows (1) As of December 31, 2018 2019 RMB RMB Beginning balance (current and noncurrent) 2,110,428 3,286,025 Additions 3,214,400 2,236,638 Deductions (2,038,803 ) (2,293,893 ) Ending balance (current and noncurrent) 3,286,025 3,228,770 Deferred revenue, current 1,765,085 1,670,076 Deferred revenue, non-current 1,520,940 1,558,694 (1) Amounts presented are inclusive of VAT (see VAT in Note 2) . Deferred revenue primarily consists of educational service fees received from customers for which the Group’s revenue recognition criteria have not been met. Deferred revenue balance will be recognized as revenue once the criteria for revenue recognition are met. The current portion of deferred revenue as of January 1, 2018 and January 1, 2019 were substantially all recognized as revenue during the years ended December 31, 2018 and 2019, respectively. The Group’s remaining performance obligations, representing the amount of the transaction price for which service has not been provided,

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt	12. LONG-TERM DEBT On August 29, 2018 and November 21, 2018, the Group entered into two s The Group repaid RMB1,875 and RMB32,500 for the principals of loans during the years ended December 31, 2018 and 2019, respectively.

Ordinary Shares

Ordinary Shares	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Ordinary Shares	1 3 . ORDINARY SHARES On September 18, 2015, the Company authorized 1,000,000,000 shares of a par value of US$0.00005 (equivalent to RMB0.0003) per share and issued 1 ordinary share at par value at incorporation. In March 2018, the Company completed its IPO and issued 16,478,275 ADSs (representing 659,131 Class A ordinary shares). The net proceeds raised from IPO were RMB1,109,517, Upon the completion of IPO in March 2018, Series A, Series B and Series B+ Preferred Shares outstanding then were converted into different classes of ordinary shares on a 1:1 basis. 954,274 Series A convertible redeemable preferred shares were converted into 954,274 Class A ordinary shares; 826,389 Series B convertible redeemable preferred shares were converted into 826,389 Class B ordinary shares; and 141,264 Series B+ convertible redeemable preferred shares were converted into 141,264 Class A ordinary shares. Meanwhile, 4,329,000 ordinary shares outstanding then were designated to 63,714 Class A ordinary shares and 4,265,286 Class C ordinary shares, respectively. On August 29, 2018, the Company’s Board of Directors approved a share repurchase program under which the Company was authorized to repurchase up to US$50,000 of its Class A ordinary shares in the form of ADSs over the following 12 months. On November18, 2019, the Company’s Board of Directors approved the extension of the repurchase program to August 23, 2020. 1,127,055 ADSs and 1,297,363 ADSs (equivalent to 45,082 and 51,895 Class A ordinary shares, respectively) were repurchased for the years ended December 31, 2018 and 2019 at a total consideration of RMB34,828 and RMB30,793, respectively. The repurchased shares were presented as treasury stock on the consolidated balance sheets as of December 31, 2018 and 2019. During the year ended December 31, 2019, 6,600 Class C ordinary shares were converted into 6,600 Class A ordinary shares.

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement	1 4 . FAIR VALUE MEASUREMENT Measured or disclosed at fair value on a recurring basis The Group measured its financial assets and liabilities, including cash and cash equivalents, short-term investments and long-term debt on a recurring basis as of December 31, 2018 and 2019. Cash and cash equivalents are classified within Level 1 of the fair value hierarchy because they are valued based on the quoted market price in an active market. The carrying amounts of short-term investments approximate their fair values due to their short-term maturity and are within Level 2 of the fair value hierarchy. The carrying amount of long-term debt approximates fair value as its interest rates are at the same level of current market yield for comparable debts. Measured or disclosed at fair value on a non-recurring basis The Group measures long-term investments at fair value on a nonrecurring basis whenever events or changes in circumstances indicate that the carrying value may no longer be recoverable.

Share Incentive Plan

Share Incentive Plan	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share Incentive Plan	1 5 . SHARE INCENTIVE PLAN 2017 Share Incentive Plan In October 2017, the shareholders of the Company approved the 2017 Share Incentive Plan (the “2017 ESOP”) under which the Company can grant a maximum of 483,846 ordinary shares. On August 24, 2018, the Company further approved an additional 345,503 ordinary shares for issuance, and therefore, 829,349 ordinary shares reserved for issuance under the 2017 ESOP. Scheme I On October 20, 2017, the Company granted 363,452 options under the 2017 ESOP for an exercise price of $0.0047 (equivalent to RMB0.0312). Vesting of Options The options shall vest and become exercisable immediately at the grant date. Exercise of Options The options shall be exercisable before the date of expiration. Expiration of Options Any unexercised option shall be immediately forfeited upon the date of the Company’s IPO. The entire 363,452 options granted under this scheme were exercised at the grant date and a compensation expense of RMB 205,630 was recorded for the year ended December 31, 2017. Scheme II On October 20, 2017, the Company granted 66,053 options under the 2017 ESOP for an exercise price of $84.75 (equivalent to RMB560.95). Vesting of Options The options shall vest and become exercisable in the installments of 10%, 20%, 30% and 40%, respectively on the first, second, third and fourth anniversary of the date of the Company’s IPO. Exercise of Options The options shall be exercisable before the date of expiration. Any unexercised option shall be immediately forfeited upon the tenth anniversary of October 20, 2017. The vesting and exercisability of options granted under Scheme II of the 2017 ESOP are both upon the IPO which is not assessed as probable until the effective date of the IPO. Therefore, no share-based compensation expenses were accrued for the year ended December 31, 2017. Upon the completion of the Company's IPO in March 2018, a compensation expense of RMB2,751 was recorded for the year ended December 31, 2018. 1 5 . SHARE INCENTIVE PLAN - continued Scheme II - continued A summary of option activities and changes during the year ended December 31, 2019 were presented below: Weighted- average Weighted- Weighted- remaining Aggregated average Number of average contractual intrinsic grant date Share option shares exercise price term(years) value fair value RMB RMB RMB Outstanding, December 31, 2018 51,831 560.95 8.81 — 271.90 Forfeited (5,200 ) 560.95 — — 271.90 Outstanding, December 31, 2019 46,631 560.95 7.81 — 271.90 The Company calculated the estimated fair value of the options on the respective grant dates using the binomial option pricing model with the assistance from an independent valuation firm, with the following assumptions used. October 20, Grant Dates 2017 Risk-free interest rate 2.0%-2.4% Volatility 32%-45% Expected dividend yield 0% Exercise multiples 2.2-2.8 Exercise price 0.0312-560.95 Life of option (years) 0.53-10 Fair value of underlying ordinary share 565.80 (1) Risk free rate of interest Risk-free interest rate was estimated based on the yield to maturity of US Sovereign Strips Curve with maturity date closest to the life to expiration, plus country default spread of China as of the valuation dates. (2) Volatility The volatility factor estimated was based on the daily share price volatility of comparable companies for an observation period that matches the life to expiration of share options. (3) Dividend Yield The management does not have any dividend policy after IPO. Hence, the dividend payout ratio is assumed to be 0%. (4) Exercise multiples Exercise multiple is based on empirical research on typical employee stock option exercising behavior. In addition to the Share Incentive Plans disclosed On May 17, 2018, the Company’s Board of Directors approved to award certain independent directors for their services rendered for the year ended December 31, 2018.The awards would be settled by issuing a variable number of the Company's shares valued at RMB1,100 and the share number is determined by dividing RMB1,100 by the average closing price during certain periods of time. The Group accounted for the awards to the independent directors as share-based compensation classified as liabilities which was included in accrued expenses and other current liabilities. 1 5 . SHARE INCENTIVE PLAN - continued Scheme II - continued Total share-based compensation expense of share-based awards granted to employees, certain directors and management recognized for the years ended December 31, 2017, 2018 and 2019 were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Cost of revenues 19,244 314 317 Sales and marketing expenses 75,237 773 674 General and administrative expenses 194,282 2,764 1,979 288,763 3,851 2,970 As of December 31, 2019, the unrecognized share-based compensation expenses related to share options were RMB7,421, which are expected to be recognized over a weighted average period of 2.2

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	1 6 . LEASES Operating leases The Group's leases consist of operating leases for administrative office spaces and enrollment centers in different cities in the PRC. For leases with terms greater than 12 months, the Group records the related asset and lease liability at the present value of lease payments over the term. As of December 31, 2019, the Group did not have additional operating leases that have not yet commenced. As of December 31, 2019, the Group had no long-term leases that were classified as a financing lease. Short-term lease cost for the year ended December 31, 2019 was immaterial. Total operating lease expenses for the year ended December 31, 2019 were RMB96,165, recorded in cost of revenues, selling expenses, research and development expenses and general and administrative expenses on the consolidated statements of operations. Year ended December 31,2019 RMB Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 85,717 Right-of-use assets obtained in exchange for new lease obligations: Operating leases 126,099 Weighted average remaining lease term Operating leases 12.2 years Weighted average discount rate Operating leases 6.7% The following is a maturity analysis of the annual undiscounted cash flows for lease liabilities as of December 31, 2019: RMB 2020 91,182 2021 75,342 2022 72,690 2023 72,576 2024 75,026 2025 and thereafter 587,588 Total future lease payments 974,404 Less: Imputed interest 317,922 Total lease liability balance 656,482 1 6 . LEASES - continued Operating leases - continued Future minimum payments under non-cancelable operating leases related to offices and enrollment centers consisted of the following at December 31, 2018: RMB 2019 110,796 2020 97,949 2021 90,347 2022 83,251 2023 and thereafter 698,995 1,081,338 Payments under operating leases are expensed on the straight-line basis over the periods of their respective leases. The terms of the leases do not contain rent escalation or contingent rents. For the years ended December 31, 2017, 2018 and 2019, the total rental expenses for all operating leases amounted to RMB65,214, RMB107,331 and RMB96,165, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	1 7 . INCOME TAXES Cayman Islands Under current law of Cayman Islands, the Company is not subject to income or capital gains taxes. In addition, dividends payments are not subject to tax withholding in the Cayman Islands. Hong Kong The Company’s subsidiary, Sunlands HK is located in Hong Kong and is subject to a two-tiered income tax rate for taxable income earned in Hong Kong with effect from April 1, 2018. The first HK$2 million of profits earned by Sunlands HK will be taxed at 8.25%, while the remaining profits will continue to be taxed at the existing 16.5% tax rate. No provision for Hong Kong profits tax has been made in the consolidated financial statements as it has no assessable income for the years ended December 31, 2017, 2018 and 2019. China The Group’s subsidiaries, VIEs and VIEs’ subsidiaries incorporated in the PRC were generally subject to a corporate income tax rate of 25%. The Enterprise Income Tax Law (the “EIT Law”) of the PRC, effective since January 1, 2008, applies a uniform 25% enterprise income tax rate to all resident enterprises in China, including foreign invested enterprises. Beijing Sunlands was qualified as “high and new technology enterprise strongly supported by the State” (“HNTE”) and was accordingly entitled to a preferential tax rate of 15% from calendar years 2016 through 2021 and is expected to be subject to an EIT rate of 15% as long as it maintains its status as a HNTE. The income tax expenses in the consolidated statements of operations were nil, nil and 2,440 for the three years ended December 31, 2019, respectively. 17. INCOME TAXES - continued China - continued The reconciliation of the effective tax rate and the statutory income tax rate applicable to PRC operations is as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Loss before income tax expenses (913,824 ) (928,660 ) (392,589 ) Income tax expenses computed at applicable tax rates of 25% (228,456 ) (232,165 ) (98,147 ) Non-deductible and super deduction expenses (3,490 ) (8,013 ) (40,711 ) Effect of tax holidays and preferential tax rates 130,296 64,029 22,595 Change in valuation allowance 101,650 176,149 118,703 Income tax expenses — — 2,440 If the tax holidays granted to Beijing Sunlands were not available, the Group’s income tax expenses would have been nil, which would have no impact on the basic and diluted net loss per ordinary share attributable to the Company, for the three years ended December 31, 2019. Deferred taxes reflect the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The components of deferred taxes are as follows: As of December 31, 2018 2019 RMB RMB Deferred tax assets Accrued expenses 13,270 6,511 Advertising expenses carry-forwards 87,600 58,288 Net operating loss carry-forwards 285,018 525,305 Total deferred tax assets 385,888 590,104 Less: valuation allowance (385,888 ) (504,591 ) Deferred tax assets, net — 85,513 Deferred tax liabilities Deferred costs — (87,954 ) Total deferred tax liabilities — (87,954 ) As of December 31, 2019, the Company’ subsidiaries, VIEs and VIEs’ subsidiaries registered in the PRC have total net operating loss carry forwards of RMB2,923,067, which would expire on various dates through December 31, 2020 to December 31, 2029. The authoritative guidance requires that the Group recognizes the impact of a tax position in the financial statements if that position is more likely than not of being sustained upon audit by the tax authority, based on the technical merits of the position. Under PRC laws and regulations, arrangements and transactions among related parties may be subject to examination by the PRC tax authorities. If the PRC tax authorities determine that the contractual arrangements among related companies do not represent a price under normal commercial terms, they may make adjustments to the companies’ income and expenses. A transfer pricing adjustment could result in additional tax liabilities. The Group did not have any significant unrecognized uncertain tax positions as of and for the years ended December 31, 2017, 2018 and 2019. In addition, uncertainties exist with respect to how the current income tax law in the PRC applies to the Group’s overall operations, and more specifically, with regard to tax residency status. The New EIT Law includes a provision specifying that legal entities organized outside of the PRC will be considered residents for Chinese income tax purposes if the place of effective management or control is within the PRC. The implementation rules to the New EIT Law provide that non-resident legal entities will be considered PRC residents if substantial and overall management and control over the manufacturing and business operations, personnel, accounting and properties, occurs within the PRC. Despite the present uncertainties resulting from the limited PRC tax guidance on the issue, the Group does not believe that the legal entities organized outside of the PRC within the Group should be treated as residents for EIT law purposes. If the PRC tax authorities subsequently determine that the Company and its subsidiaries registered outside the PRC should be deemed resident enterprises, the Company and its subsidiaries registered outside the PRC will be subject to the PRC income taxes, at a rate of 25%.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	1 8 . NET LOSS PER SHARE The number of ordinary shares used in the calculation of net loss per share for the year ended December 31, 2017 reflected the Group's 2017 Reorganization as described in Note 1. As of December 31, 2017 2018 2019 RMB RMB RMB Numerator: Net loss attributable to Sunlands Technology Group used in basic and diluted net loss per share: Net loss attributable to ordinary shareholders (918,578 ) (927,022 ) (394,817 ) Denominator: Weighted average ordinary shares outstanding used in computing basic and diluted net loss per share 3,945,864 6,294,870 6,830,058 Net loss per share Basic and diluted (232.80 ) (147.27 ) (57.81 ) Given the Company's loss making position for the years ended December 31, 2017, 2018 and 2019, the effect of potential issuances of shares for the convertible redeemable preferred shares and share options would be anti-dilutive: (1) The outstanding 954,274 Series A Preferred Shares, 826,389 Series B Preferred Shares and 141,264 Series B+ Preferred Shares were not considered in the computation of diluted net loss per share for the year ended December 31, 2017; (2) 51,831 share options were not considered in the computation of diluted net loss per share for the year ended December 31, 2018. (3) 46,631 share options were not considered in the computation of diluted net loss per share for the year ended December 31, 2019 .

Related Party Transaction

Related Party Transaction	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Amounts Due From/To Related Parties	19 . RELATED PARTY TRANSACTION (1) The table below sets forth the major related parties and their relationship with the Group. Name of related parties Relationship with the Group Shangde Jiaxun Entity controlled by the Founder and the CEO (Note 1) (2) The related party transactions were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Disposal of a subsidiary to a related party 1,000 — — In October 2017, the Group disposed a subsidiary to Shangde Jiaxun with a total consideration of RMB1,000 and a gain of RMB178 was recorded in the Group’s consolidated statement of operations

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	2 0 . COMMITMENTS AND CONTINGENCIES Investment commitment The Group was obligated to pay RMB34,837 for the long-term investments as of December 31, 2019. Contingencies From time to time, the Group is subject to legal proceedings and claims incidental to the conduct of its business. The Group accrues the liability when the loss is probable and reasonably estimable.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Reporting	2 1 . SEGMENT REPORTING The Group’s chief operating decision maker (“CODM”) has been identified as the Chief Executive Officer of the Group, who reviews financial information of operating segments when making decisions about allocating resources and assessing performance of the Group. An operating segment is a component of the Group that engages in business activities from which it may earn revenues and incur expenses, and is identified on the basis of the internal financial reports that are provided to and regularly reviewed by the Group’s CODM. For the years ended December 31, 2017, 2018 and 2019, the Group’s CODM reviewed the financial information of the education business carried out by the Group on a consolidated basis. The Group has one operating segment, which is the provision of online education service. The Group operates solely in the PRC and all of the Group’s long-lived assets are located in the PRC.

Employee Defined Contribution P

Employee Defined Contribution Plan	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Defined Contribution Plan	2 2 . EMPLOYEE DEFINED CONTRIBUTION PLAN Full time employees of the Group in the PRC participate in a government mandated defined contribution plan, pursuant to which certain pension benefits, medical care, employee housing fund and other welfare benefits are provided to employees. Chinese labor regulations require that the PRC subsidiaries of the Group make contributions to the government for these benefits based on certain percentages of the employees’ salaries. The Group has no legal obligation for the benefits beyond the contributions made. The total amounts for such employee benefits, which were expensed as incurred, were RMB164,775, RMB228,376 and RMB182,132, for the years ended December 31, 2017, 2018 and 2019, respectively.

Restricted Net Assets

Restricted Net Assets	12 Months Ended
	Dec. 31, 2019
Restricted Net Assets [Abstract]
Restricted Net Assets	23. RESTRICTED NET ASSETS Relevant PRC statutory laws and regulations permit payments of dividends by the Group’s PRC subsidiaries only out of their retained earnings, if any, as determined in accordance with PRC accounting standards and regulations. The results of operations reflected in the financial statements prepared in accordance with U.S. GAAP differ from those reflected in the statutory financial statements of the Company’s subsidiaries. In accordance with the Regulations on Enterprises with Foreign Investment of China and their articles of association, a foreign invested enterprise established in the PRC is required to provide certain statutory reserves, namely general reserve fund, the enterprise expansion fund and staff welfare and bonus fund which are appropriated from net profit as reported in the enterprise’s PRC statutory accounts, which is included in retained earnings accounts in equity section of the consolidated balance sheets. A wholly-owned foreign invested enterprise is required to allocate at least 10% of its annual after-tax profit to the general reserve until such reserve reaches 50% of its respective registered capital based on the enterprise’s PRC statutory accounts. Appropriations to the enterprise expansion fund and staff welfare and bonus fund are at the discretion of the board of directors for all foreign invested enterprises. The aforementioned reserves can only be used for specific purposes and are not distributable as cash dividends. If any PRC subsidiary incur debt on its own behalf in the future, the instruments governing the debt may restrict their ability to pay dividends or make other payments to the Group. Any limitation on the ability of the PRC subsidiaries to distribute dividends or other payments to their respective shareholders could materially and adversely limit the ability to grow, make investments or acquisitions that could be beneficial to pay dividends. Additionally, in accordance with the Company Law of the PRC, a domestic enterprise is required to provide statutory common reserve at least 10% of its annual after-tax profit until such reserve reaches 50% of its respective registered capital based on the enterprise’s PRC statutory accounts. The Group’s provision for the statutory common reserve is in compliance with the aforementioned requirement of the Company Law. A domestic enterprise is also required to provide for discretionary surplus reserve, at the discretion of the board of directors, from the profits determined in accordance with the enterprise’s PRC statutory accounts. The aforementioned reserves can only be used for specific purposes and are not distributable as cash dividends. Because the Group’s entities in the PRC can only be paid out of distributable profits reported in accordance with PRC accounting standards, the Group’s entities in the PRC are restricted from transferring a portion of their net assets to the Company. The restricted amounts include the paid-in capital and statutory reserves of the Group’s entities in the PRC. The aggregate amount of paid-in capital and statutory reserves, which is the amount of net assets of the Group’s entities in the PRC (mainland) not available for distribution, were RMB1,189,308 as of December 31, 2019.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	24. SUBSEQUENT EVENTS Since January 2020, a strain of coronavirus, or COVID-19 has spread rapidly to many parts of China. The Self-taught Higher Education Examination, or the STE, a state-administered exam in China for learners pursuing associate diplomas or bachelor’s degrees originally scheduled in April 2020, has been postponed by the Ministry of Education of the PRC as a result of the COVID-19 pandemic. In March 2020, the Group determined to adjust the service period to accommodate the rescheduled STE.

Condensed Financial Information

Condensed Financial Information Of Parent Company	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Financial Information of Parent Company	CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY BALANCE SHEETS (Amounts in thousands, except for share and per share data) As of December 31, 2018 2019 2019 RMB RMB US$ ASSETS Cash and cash equivalents 1,086,521 1,125,048 161,603 Short-term investments 441,513 — — Prepaid expenses and other current assets 11,950 1,244 177 Amounts due from subsidiaries 695,194 1,093,781 157,112 Total current assets 2,235,178 2,220,073 318,892 Non-current assets Other non-current assets — 26,849 3,857 Total non-current assets 26,849 3,857 TOTAL ASSETS 2,235,178 2,246,922 322,749 LIABILITIES AND SHAREHOLDERS’ DEFICIT LIABILITIES Current liabilities Accrued expenses and other current liabilities 6,268 6,942 997 Total current liabilities 6,268 6,942 997 Non-current liabilities Investment in subsidiaries 2,556,801 2,970,297 426,656 Other non-current liabilities 11,228 7,834 1,125 Total non-current liabilities 2,568,029 2,978,131 427,781 TOTAL LIABILITIES 2,574,297 2,985,073 428,778 SHAREHOLDERS’ DEFICIT Class A ordinary shares (par value of US$0.00005, 796,062,195 shares authorized; 1,818,383 and 1,830,183 shares issued as of December 31, 2018 and December 31, 2019, respectively; 1,773,301 and 1,728,006 shares outstanding as of December 31, 2018 and 2019, respectively) 1 1 — Class B ordinary shares (par value of US$0.00005, 826,389 shares authorized; 826,389 and 826,389 shares issued and outstanding as of December 31, 2018 and 2019, respectively) — — — Class C ordinary shares (par value of US$0.00005, 203,111,416 shares authorized; 4,265,286 and 4,258,686 shares issued and outstanding as of December 31, 2018 and December 31,2019, respectively) 1 1 — Treasury stock — — — Additional paid-in capital 2,391,822 2,363,999 339,567 Accumulated other comprehensive income 118,827 142,435 20,460 Accumulated deficit (2,849,770 ) (3,244,587 ) (466,056 ) TOTAL SHAREHOLDERS’ DEFICIT (339,119 ) (738,151 ) (106,029 ) TOTAL LIABILITIES AND SHAREHOLDERS’ DEFICIT 2,235,178 2,246,922 322,749 ADDITIONAL INFORMATION—FINANCIAL STATEMENT SCHEDULE I CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY STATEMENTS OF OPERATIONS (Amounts in thousands, except for share and per share data) Years ended December 31, 2017 2018 2019 RMB RMB RMB US$ Cost of revenues (19,244 ) (475 ) (317 ) (46 ) Gross profit (19,244 ) (475 ) (317 ) (46 ) Operating expenses Sales and marketing expenses (75,237 ) (820 ) (674 ) (97 ) General and administrative expenses (194,878 ) (15,335 ) (22,850 ) (3,282 ) Total operating expenses (270,115 ) (16,155 ) (23,524 ) (3,379 ) Loss from operations (289,359 ) (16,630 ) (23,841 ) (3,425 ) Interest income 1,592 33,525 38,331 5,505 (Loss)/profit before income tax expenses (287,767 ) 16,895 14,490 2,080 Income tax expenses — — — — Loss from investment in subsidiaries (630,947 ) (943,781 ) (409,307 ) (58,793 ) Net loss (918,714 ) (926,886 ) (394,817 ) (56,713 ) ADDITIONAL INFORMATION—FINANCIAL STATEMENT SCHEDULE I CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY STATEMENTS OF COMPREHENSIVE LOSS (Amounts in thousands, except for share and per share data) Years ended December 31, 2017 2018 2019 RMB RMB RMB US$ Net loss (918,714 ) (926,886 ) (394,817 ) (56,713 ) Other comprehensive (loss)/income, net of tax effect of nil: Change in cumulative foreign currency translation adjustments (8,759 ) 127,586 23,608 3,391 Total comprehensive loss (927,473 ) (799,300 ) (371,209 ) (53,322 ) . ADDITIONAL INFORMATION—FINANCIAL STATEMENT SCHEDULE I CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY STATEMENTS OF CASH FLOWS (Amounts in thousands, except for share and per share data) Years ended December 31, 2017 2018 2019 RMB RMB RMB US$ CASH FLOWS FROM OPERATING ACTIVITIES Net loss (918,714 ) (926,886 ) (394,817 ) (56,713 ) Adjustments to reconcile net loss to net cash generated from operating activities: Share-based compensation 288,763 3,851 2,970 427 Loss from investment in subsidiaries 813,313 1,032,235 413,496 59,395 Amounts due to subsidiaries (751,735 ) (185,537 ) (398,587 ) (57,253 ) Prepaid expenses and other current assets — (19,276 ) 18,032 2,594 Other non-current liabilities — 11,228 (3,394 ) (488 ) Accrued expenses and other current liabilities 75 4,231 1,531 220 Net cash used in operating activities (568,298 ) (80,154 ) (360,769 ) (51,818 ) CASH FLOWS FROM INVESTING ACTIVITIES Purchase of short-term investments — (814,539 ) — — Proceeds from maturity of short-term investments — 396,852 436,228 62,660 Loan to employees — — (26,849 ) (3,857 ) Net cash (used in)/ generated from investing activities — (417,687 ) 409,379 58,803 CASH FLOWS FROM FINANCING ACTIVITIES Amounts due from related parties — 245,654 — — Payment for share repurchase — (33,971 ) (31,650 ) (4,546 ) Proceeds from initial public offering, Net of issuance cost of 80,128 — 1,109,517 — — Capital contribution from series B and B+ convertible redeemable preferred shareholders 732,709 — — — Net cash generated from/ (used in) financing activities 732,709 1,321,200 (31,650 ) (4,546 ) Effect of exchange rate charges (8,759 ) 107,510 21,567 3,095 Net increase in cash and cash equivalents 155,652 930,869 38,527 5,534 Cash and cash equivalents at beginning of the year — 155,652 1,086,521 156,069 Cash and cash equivalents at end of the year 155,652 1,086,521 1,125,048 161,603 ADDITIONAL INFORMATION—FINANCIAL STATEMENT SCHEDULE I CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY NOTES TO FINANCIAL STATEMENTS (Amounts in thousands, except for share and per share data) 1. Schedule I has been provided pursuant the requirements of Rule 12-04(a) and 5-04(c) of Regulation S-X, which require condensed financial information as to the financial position, changes in financial position and results of operations of a parent company as of the same dates and for the same periods for which audited consolidated financial statements have been presented when the restricted net assets of consolidated subsidiaries exceed 25 percent of consolidated net assets as of the end of the most recently completed fiscal year. 2. The condensed financial information of Sunlands Technology Group has been prepared using the same accounting policies as set out in the accompanying consolidated financial statements except that the equity method has been used to account for investments in its subsidiaries. 3. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The footnote disclosures contain supplemental information relating to the operations of the Group and, as such, these statements should be read in conjunction with the notes to the Consolidated Financial Statements of the Group. No dividend was paid by the Group's subsidiaries to their parent company in 2017, 2018 and 2019.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of presentation and use of estimates	Basis of presentation and use of estimates The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the balance sheet dates and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in the Group’s financial statements include, but are not limited to, consolidation of VIEs, valuation allowance for deferred tax assets, the variable consideration to be earned for certain online courses, useful lives of property and equipment, impairment of long-term assets and valuation of share-based compensation. Actual results could materially differ from those estimates.
Principles of consolidation	Principles of consolidation The consolidated financial statements include the financial statements of the Company and its subsidiaries, and VIEs and VIEs’ subsidiaries. All intercompany transactions and balances were eliminated upon consolidation.
Foreign currency translation and transactions	Foreign currency translation and transactions The Group’s reporting currency is Renminbi (“RMB”). The functional currency of the subsidiaries incorporated outside the mainland China is United States dollar (“US dollar” or “US$”). The functional currency of all the other subsidiaries and the VIEs and VIEs’ subsidiaries is RMB. Monetary assets and liabilities denominated in currencies other than the applicable functional currencies are translated into the functional currencies at the prevailing rates of exchange at the balance sheet date. Nonmonetary assets and liabilities are remeasured into the applicable functional currencies at historical exchange rates. Revenues and expenses are translated using the average rate of exchange in effect during the reporting period. Translation adjustments are reported and shown as a separate component of other comprehensive loss in the consolidated statements of changes in shareholders’ deficit and the consolidated statements of comprehensive loss. Transactions in currencies other than the functional currencies during the year are converted into the applicable functional currencies at the applicable rates of exchange prevailing at the dates of the transactions. Transaction gains and losses are recorded in the consolidated statements of operations.
Convenience Translation	Convenience Translation The Group’s business is primarily conducted in China and all of the revenues are denominated in RMB. However, periodic reports made to shareholders will include current period amounts translated into US dollars using the then current exchange rates, for the convenience of the readers. Translations of balances in the consolidated balance sheets, and the related consolidated statements of operations, shareholders’ deficit and cash flows from RMB into US dollars as of and for the year ended December 31, 2019 are solely for the convenience of the readers and were calculated at the rate of US$1.00= RMB6
Cash and cash equivalents	Cash and cash equivalents Cash and cash equivalents comprise cash at banks and on hand and term deposits, which have original maturities of three months or less when purchased and are subject to an insignificant risk of changes in value. The carrying value of cash equivalents approximates market value.
Short-term investments	Short-term investments Short-term investments consist of financial products with unsecured principal purchased from commercial banks and financial institutions which have original maturities of less than one year. The carrying amount of these short-term investments approximates their fair values due to the short-term maturities of these investments and are carried at amortized cost. The Group reviews its short-term investments for impairment whenever an event or circumstance indicates that impairment has occurred. The Group considers available quantitative and qualitative evidence in evaluating the potential impairment of its short-term investments. An impairment charge is recorded in the consolidated statements of operations if the carrying amount of an investment exceeds the investment’s fair value.
Long-term investments	Long-term investments Investee companies over which the Group has the ability to exercise significant influence, but does not have a controlling interest through investment in common shares or in-substance common shares, are accounted for using the equity method. Significant influence is generally considered to exist when the Group has an ownership interest in the voting stock of the investee between 20% and 50%, and other factors, such as representation on the investee’s board of directors, voting rights and the impact of commercial arrangements, are also considered in determining whether the equity method of accounting is appropriate. For certain investments in limited partnerships, where the Group holds less than a 20% equity or voting interest, the Group may also have significant influence. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Long-term investments - continued Under the equity method of accounting, the Group initially records its investment at cost and subsequently recognizes the Group’s proportionate share of each equity investee’s net income or loss after the date of investment into earnings and adjusts the investment carrying amount accordingly. The Group reviews its equity method investments for impairment whenever an event or circumstance indicates that any other-than-temporary impairment has occurred. The Group considers available quantitative and qualitative evidence in evaluating potential impairment of its equity method investments. An impairment charge is recorded when the carrying amount of the investment exceeds its fair value and this condition is determined to be other-than-temporary.
Fair value	Fair value Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Group considers the principal or most advantageous market in which it would transact and it considers assumptions that market participants would use when pricing the asset or liability. Authoritative literature provides a fair value hierarchy which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The level in the hierarchy within which the fair value measurement in its entirety falls is based upon the lowest level of input that is significant to the fair value measurement as follows: Level 1 Level 1 applies to assets or liabilities for which there are quoted prices in active markets for identical assets or liabilities. Level 2 Level 2 applies to assets or liabilities for which there are inputs other than quoted prices included within Level 1 that are observable for the asset or liability such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical assets or liabilities in markets with insufficient volume or infrequent transactions (less active markets); or model-derived valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data. Level 3 Level 3 applies to assets or liabilities for which there are unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of the assets or liabilities.
Financial instruments	Financial instruments The Group’s financial instruments consist primarily of cash and cash equivalents, short-term investments, other current liabilities and long-term debt. The carrying amount of long-term debt approximates fair value as its interest rates are at the same level of current market yield for comparable debts. The carrying amounts of other financial instruments approximate their fair values due to short-term maturities.
Property and equipment, net	Property and equipment, net Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the assets, as follows: Category Estimated useful life Buildings 36-37 years Leasehold and buildings improvements Shorter of lease term or expected useful life Electronic and office equipment 3-5 years 2. SIGNIFICANT ACCOUNTING POLICIES - continued Property and equipment, net - continued Repair and maintenance costs are charged to expense as incurred, whereas the cost of renewals and betterment that extends the useful lives of property and equipment are capitalized as additions to the related assets. Retirements, sales and disposals of assets are recorded by removing the cost and accumulated depreciation from the asset and accumulated depreciation accounts with any resulting gain or loss reflected in the consolidated statements of operations.
Intangible assets, net	Intangible assets, net Intangible assets are amortized using the straight-line basis over the estimated useful lives as follows: Category Estimated useful life Computer software 3 years License 5 years
Impairment of long-lived assets	Impairment of long-lived assets The Group reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may no longer be recoverable. When these events occur, the Group measures impairment by comparing the carrying value of the long-lived assets to the estimated undiscounted future cash flows expected to result from the use of the assets and their eventual disposition. If the sum of the expected undiscounted cash flow is less than the carrying amount of the assets, the Group would recognize an impairment loss based on the fair value of the assets. The Group did not record any impairment losses on its long-lived assets during the years ended December 31, 2017, 2018 and 2019.
Revenue recognition, Deferred Revenue and Cost of revenue	Revenue recognition The Group early adopted the accounting standard Revenue from Contracts with Customers (ASC 606) as of January 1, 2017 using the full retrospective method which requires the Group to present its financial statements for all periods as if ASC 606 had been applied to all prior periods. The Group did not apply practical expedients as provided under ASC 606. The Group follows five steps for its revenue recognition under ASC 606: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Group’s revenue is reported net of discount, business tax, value added tax and related surcharges. The primary sources of the Group’s revenues are as follows: Online education services For online education services, the Group provides an integrated online education service package to students, including online live streaming audio-video interactive course content, recorded previous live audio-video course content, quiz banks, online chat rooms, and educational contents. The services and goods provided in the package are highly interdependent and interrelated in the context of the contract and are only considered accessory services to the online live streaming and recorded courses which are not distinct and are not sold standalone. Therefore, the Group's integrated online education services package is accounted for as a single performance obligation. The weighted average service period for degree- or diploma-oriented post-secondary courses and professional certification preparation and professional skills courses was 32 months and 19 months, respectively, for the year ended December 31, 2019. The transaction price of the integrated online education service package is determined by the contract amount net of any discounts. Students are offered a full, unconditional refund within 24 hours upon enrollment. Prior to June 2019, undelivered courses was eligible for refund, excluding registration fees, within 7 days after enrollment. For course contracts entered after June 2019, undelivered courses is eligible for refund during the entire service period, excluding registration fees. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Revenue recognition – continued Online education services – continued Revenues for online education services are recognized on a straight line basis over the service period from the registration day to the day on which the service period ends. For certain online courses, the Group also provided students the right to apply for refund for the delivered courses if certain pre-agreed conditions are achieved. The Group estimated the variable consideration to be earned to the extent it was probable that a significant reversal of cumulative revenue recognized would not occur when the uncertainty associated with the variable consideration was resolved and recognized revenue over time from the registration day to the day on which the service period ended on a straight line basis. The Group's estimates of variable consideration and determination of whether to include estimated amounts in the transaction price were based largely on an assessment of the Group's anticipated performance and all information (historical, current and forecasted) that was reasonably available. For certain online courses, the service period includes a regular period plus an extended period. The Group offers students an extended service period after the regular period if certain pre-agreed conditions are met. Based on historical passing rates, and forecasted passing rates due to continuous improvement of service quality, the Group applies and categorizes the students by portfolio (1) eligible to extended period and (2) not eligible to extended period and estimates the portion of each portfolio. The Group recognizes the revenue on each portfolio over time from the registration day to the day on which the service is expected to end on a straight line basis. For certain online courses, the Group offers a bundled service including an integrated online education service package with insurance coverage for tuition refund. If certain refund conditions are met, students could claim the insurance equal to full or partial amount of the service fee. The Group identifies that the integrated online education service package and the insurance service are two separate performance obligations as students benefit from each service on its own and they are separately identifiable in the contract. The Group records revenue generated from online education services with insurance coverage on a gross basis as the Group is acting as the principal to fulfill all obligation and control all the services transferred to the students. The Group's deferred costs represent the unamortized incremental sales commission relating to obtaining of customers contract, and the contract liability primarily consists of deferred revenue. Student Financing The Group offers an installment payment option to students, under which the students obtain loans, from accredited credit sources (“Loan Companies”) for the purpose of satisfying the student’s tuition payment due. The borrowing student is obligated to repay the loan principal in installments over periods ranging from 3 months to 18 months to the Loan Companies, while the Group agrees with the Loan Companies to bear the student’s interest expense and service fees. The Loan Companies remit the tuition to the Group for students to complete the registration. The interest expense and service fees are recorded as a reduction of the transaction price. Commission revenue The Group earns commission revenue by providing referral services to third party education institutions. Commission revenue is recognized when the referred students registered at the third party education institutions and the tuition fees are paid, by when the performance obligation is satisfied. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Revenue recognition – continued Deferred Revenue Revenues related to the Group’s online courses are recognized over time. Deferred revenue consists of tuition fees received from students for which services have not yet been provided to students. Cost of revenue Cost of revenues consist of expenditures incurred in the generation of the Group’s revenue, includes but not limited to salaries and benefits paid to teachers, related rental expenses, server management costs, bandwidth costs, payment processing costs, insurance cost, depreciations for property and equipment and amortizations for intangible assets.
Value added taxes ("VAT")	Value added taxes (“VAT”) The Group's services are subject to VAT at the rate of 6% for general-VAT-payer entities in accordance with tax rule, except that certain subsidiaries were subject to a simple VAT collection method at a rate of 3% before June 2019.
Product development expenses	Product development expenses Product development expenses primarily consist of (i) salaries and benefits for innovation and development of course content, product and technology development personnel, and (ii) office rental, general expenses and depreciation and amortization expenses associated with the product development activities. The Group’s product development activities primarily consist of the development and enhancement of the Group’s educational content, applications and platforms. The Group has expensed all product development expenses when incurred.
Sales commission	Sales commission The incremental sales commission relating to obtaining of the customer contract and expected to be recovered is accounted for as an incremental cost of obtaining a contract and is capitalized as deferred costs when incurred. The capitalized cost is amortized in the same manner as the revenue recognized and is included in “sales and marketing expenses” in the consolidated statements of operations. Other sales commission incurred regardless of whether the contract was obtained is recognized as an expense when incurred.
Advertising expenditure	Advertising expenditure Advertising expenditure, mainly includes search engine marketing and mobile marketing expenses, is expensed when incurred and is included in sales and marketing expenses in the consolidated statements of operations. Advertising expenses were RMB499,294, RMB983,012 and RMB937,145 for the years ended December 31, 2017, 2018 and 2019, respectively.
Sales and marketing expenses	Sales and marketing expenses Sales and marketing expenses primarily consist of (i) salaries and benefits for sales and marketing personnel, (ii) search engine marketing and mobile marketing expenses and other advertising expenses, (iii) office rental, general expenses and depreciation and amortization expenses associated with the sales and marketing activities.
Leases	2. SIGNIFICANT ACCOUNTING POLICIES - continued Leases The Group leases administrative office spaces and enrollment centers in different cities in the PRC under operating leases. The Group determines whether an arrangement constitutes a lease at inception. The Group has lease agreements with lease and non-lease components, which are generally accounted for separately. The allocation of the consideration between the lease and the non-lease components is based on the relative stand-alone prices of lease components included in the lease contracts. Operating lease right-of-use assets and liabilities are recognized at lease commencement date based on the present value of remaining lease payments over the lease terms. The Group uses the implicit rate when readily determinable, or its incremental borrowing rate based on the information available, at the commencement date in determining the present value of lease payments. Certain leases include renewal options and/or termination options. Renewal options are included in the lease term if the Group is reasonably certain to exercise those options while options to terminate the lease are only included in the lease term if the Group is reasonably certain not to exercise those options. Lease expense is recorded on a straight-line basis over the lease term. For short-term leases, the Group records operating lease expense in its consolidated statements of operations on a straight-line basis over the lease term.
Government Subsidies	Government subsidies For the government subsidies not subject to further performance obligations or future returns, the Group records the amounts as other income when received from local government authority. Whereas for the government subsidies with future performance obligations, the Group recognizes those as liabilities when received until the performances obligations have been met at which time, those are recognized as other income. Government subsidies received and recorded as other income amounted to RMB3,223, RMB28,688 and RMB14,692 for the years ended December 31, 2017, 2018 and 2019, respectively.
Income taxes	Income taxes Current income taxes are provided for in accordance with the laws of the relevant tax authorities. Deferred income taxes are recognized when temporary differences exist between the tax bases of assets and liabilities and their reported amounts in the financial statements. Net operating loss carry forwards and credits are applied using enacted statutory tax rates applicable to future years. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more-likely-than-not that a portion of or all of the deferred tax assets will not be realized. The impact of an uncertain income tax position is recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant tax authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Interest and penalties on income taxes will be classified as a component of the provisions for income taxes.
Comprehensive loss	Comprehensive loss Comprehensive loss includes net loss and foreign currency translation adjustments and is reported in the consolidated statements of comprehensive loss. The Group presents the components of net loss, the components of other comprehensive loss and total comprehensive loss in two separate but consecutive statements.
Net loss per share	Net loss per share Prior to IPO, basic net loss per share is computed by dividing net loss attributable to ordinary shareholders of the Company by the weighted average number of ordinary shares outstanding during the year using the two-class method. The holders of the convertible redeemable preferred shares are entitled to share dividends on a pro rata basis, as if their shares had been converted into ordinary shares. Accordingly, the Company has used the two-class method in computing net loss per share. Under the two-class method, net loss is allocated on a pro rata basis to each class of ordinary shares and other participating securities based on their participating rights. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Net loss per share - continued After IPO, basic net loss per share is computed by dividing net loss attributable to ordinary shareholders of the Company by the weighted average number of common shares outstanding during the year. Diluted net loss per share reflects the potential dilution that could occur if securities or other contracts to issue common shares were exercised into common shares. To calculate the number of shares for diluted loss per share, the effect of the share options is computed using the treasury stock method. As the Company was loss making for the years ended December 31, 2017, 2018 and 2019, the effect of potential issuances of shares for the convertible redeemable preferred shares and share options would be anti-dilutive, and therefore basic and diluted losses per share are the same in those periods.
Share-based compensation	Share-based compensation Share-based compensation with employees is measured based on the grant date fair value of the equity instrument. Share-based compensation expenses, net of forfeitures, are recognized over the requisite service period based on a straight-line basis with a corresponding impact reflected in additional paid-in capital. Share-based compensation awards which require the issuance of a variable number of shares to settle a fixed monetary amount are recorded as liabilities.
Significant Risks and Uncertainties	Significant risks and uncertainties Foreign currency risk RMB is not a freely convertible currency. The State Administration for Foreign Exchange, under the authority of the People’s Bank of China, controls the conversion of RMB into foreign currencies. The value of RMB is subject to changes in central government policies and to international economic and political developments affecting supply and demand in the China Foreign Exchange Trading System market. The cash and cash equivalents of the Group included aggregate amounts of RMB157,103 and RMB259,612, which were denominated in RMB at December 31, 2018 and 2019, representing 12.6% and 18.5% of the cash and cash equivalents at December 31, 2018 and 2019, respectively. Concentration of credit risk Financial instrument that potentially expose the Group to significant concentration of credit risk primarily consist of cash and cash equivalents, short-term investments and prepaid expenses and other current assets. The Group places its cash and cash equivalents and short-term investments in financial institutions with high credit ratings. There are no revenues from customers which individually represent greater than 10% of the total net revenues for any year of the three years period ended December 31, 2019.
Newly adopted accounting pronouncements	Newly adopted accounting pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842). The guidance supersedes existing guidance on accounting for leases with the main difference being that operating leases are to be recorded in the statement of financial position as right-of-use assets and lease liabilities, initially measured at the present value of the lease payments. For operating leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and liabilities. For public business entities, the guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application of the guidance is permitted. In July 2018, ASU 2016-02 was updated with ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides entities with relief from the costs of implementing certain aspects of the new leasing standard. Specifically, under the amendments in ASU 2018-11, (1) entities may elect not to recast the comparative periods presented when transitioning to ASC 842 and (2) lessors may elect not to separate lease and nonlease components when certain conditions are met. Before ASU 2018-11 was issued, transition to the new lease standard required application of the new guidance at the beginning of the earliest comparative period presented in the financial statements. 2. SIGNIFICANT ACCOUNTING POLICIES - continued Newly adopted accounting pronouncements - continued The Group adopted Topic 842 on January 1, 2019 using the modified retrospective transition approach under ASU 2018-11, without adjusting comparative periods presented. The Group elected the practical expedient package to not reassess prior conclusions related to contracts containing leases, lease classification, and initial direct costs for any existing leases and the Group elected not to record on the balance sheets for leases with an initial term of twelve months or less. Upon adoption, the Group recognized right-of-use assets of RMB560.2 million and total lease liabilities (including current and non-current) of RMB607.2 million on the consolidated balance sheet as of January 1, 2019 for operating leases related to office space and enrollment centers. The adoption did not have a material impact on the Group's consolidated statements of operations or consolidated statements of cash flows, and the adoption of Topic 842 did not result in a cumulative-effect adjustment to retained earnings. Further information is disclosed in Note 16.
Recent accounting pronouncements not yet adopted	Recently issued accounting pronouncements not yet adopted In June 2016, the FASB issued ASU 2016-13, "Financial Instruments-Credit Losses (Topic 326)", which requires entities to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost. This ASU is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early application will be permitted for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. In April 25, 2019, ASU 2016-13 was updated with ASU 2019-04, which clarifies certain aspects of accounting for credit losses, hedging activities and financial instruments and provides certain alternatives for the measurement of the allowance for credit losses on accrued interest receivable. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820)—Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this ASU improve the effectiveness of fair value measurement disclosures and modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting—Chapter 8: Notes to Financial Statements, including the consideration of costs and benefits. The amendments in this ASU are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities ("VIE"). The guidance was issued in response to stakeholders' observations that Topic 810, Consolidation, could be improved in the areas of applying the VIE guidance to private companies under common control and in considering indirect interests held through related parties under common control for determining whether fees paid to decision makers and service providers are variable interests. The new standard will become effective for the Group beginning January 1, 2020, with early adoption permitted, and must be applied retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Group does not expect any material impact on its consolidated financial statements and related disclosures as a result of adopting the new standard.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Subsidiaries VIEs and VIEs' Subsidiaries	As of December 31, 2019, details of the Company’s subsidiaries, its VIEs and VIEs’ subsidiaries were as follows: Name (1) Date of establishment/ acquisition Place of establishment Percentage of direct or indirect economic ownership Principal activities Subsidiaries: Sunlands HK October 6, 2015 HongKong 100% Investment holding Wuhan Zhibo August 2, 2017 PRC 100% Provision of technical consultation and services Tianjin Sunlands July 31, 2017 PRC 100% Provision of technical consultation and services Wuhan Shangde Online Education Technology Co., Ltd. June 25, 2019 PRC 100% Provision of education services Chengdu Xinketang Cultural Communication Co., Ltd. November 4, 2019 PRC 100% Sales of educational materials and books Variable interest entities ("VIEs"): Beijing Sunlands September 27, 2013 PRC N/A* Investment holding and provision of education services Tianjin Shangde March 21, 2018 PRC N/A* Provision of education services VIEs’ subsidiaries: Beijing Shangzhi Jiaye Education Technology Co., Ltd. March 13, 2012 PRC 100% Provision of education services Beijing Shangren Chongye Education Technology Co., Ltd. September 27, 2013 PRC 100% Provision of education services Guangdong Shangde Online Education Technology Co., Ltd. October 15, 2013 PRC 100% Provision of education services Guangzhou Youhe Self-study Training School May 19, 2015 PRC 100% Provision of education services Beijing Heikuaima Education Technology Co., Ltd. (2) March 3, 2016 PRC 100% Provision of education services Shanghai Shangchi Education Technology Co., Ltd. December 22, 2016 PRC 90% Provision of education services Shanghai Shangchi Institute September 1, 2017 PRC 100% Provision of education services Guangzhou Shangzhi Side Education Technology Co., Ltd. September 28, 2017 PRC 100% Provision of education services * These entities are controlled by the Company pursuant to the contractual agreements disclosed below. (1) The English names are for identification purpose only. (2) The entity changed its legal name from Beijing Bainiao Education Technology Co., Ltd. to Beijing Heikuaima Education Technology Co., Ltd. in July 2019.
Summary Financial Information of VIEs and their Subsidiaries	The following financial information of the VIEs and their subsidiaries as of December 31, 2018 and 2019 and for each of the three years in the period ended December 31, 2019 was included in the accompanying consolidated financial statements after elimination of intercompany transactions and balances within the subsidiaries, VIEs and their subsidiaries: As of December 31, 2018 2019 RMB RMB Cash and cash equivalents 80,371 69,539 Short-term investments 587,051 38,990 Prepaid expenses and other current assets 46,601 106,568 Total current assets 818,480 284,887 Right-of-use assets — 340,302 Total non-current assets 377,856 776,783 Total assets 1,196,336 1,061,670 Accrued expenses and other current liabilities 241,204 209,727 Deferred revenue, current 1,765,085 1,162,938 Lease liabilities, current — 22,659 Total current liabilities 2,006,289 1,395,324 Deferred revenue, non-current 1,520,940 1,096,482 Lease liabilities, non-current — 358,467 Total liabilities 3,527,364 2,854,823 Years ended December 31, 2017 2018 2019 RMB RMB RMB Net revenues 970,162 1,973,985 2,049,461 Net (loss)/income (606,946 ) 393,063 590,728 Net cash generated from/(used in) operating activities 845,616 1,448,005 (480,084 ) Net cash (used in)/generated from investing activities (375,802 ) (315,198 ) 522,104 Net cash (used in)/generated from financing activities (391,237 ) 8,018 —

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Estimated Useful Lives of Property and Equipment	Property and equipment are stated at cost and are depreciated using the straight-line method over the estimated useful lives of the assets, as follows: Category Estimated useful life Buildings 36-37 years Leasehold and buildings improvements Shorter of lease term or expected useful life Electronic and office equipment 3-5 years
Summary of Estimated Useful Lives of Intangible Assets	Intangible assets are amortized using the straight-line basis over the estimated useful lives as follows: Category Estimated useful life Computer software 3 years License 5 years

Short-Term Investments (Tables)

Short-Term Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Schedule of Short-Term Investment	Short-term investments consist of various financial products with unsecured principal from financial institutions in China at original maturity less than one year when purchased. While these financial products are not publicly traded, the Group estimated that their fair value approximated the costs considering their short-term maturities and high credit quality. As of December 31, 2018 2019 RMB RMB Short-term investments 1,028,564 217,640

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following: As of December 31, 2018 2019 RMB RMB Prepaid and input VAT 58,234 120,376 Prepaid expenses (1) 10,820 21,896 Prepaid marketing expenses 23,756 16,192 Deposits (2) 4,595 8,929 Receivables from third-party payment platforms 3,886 4,367 Interest receivables 11,632 1,737 Staff advances 9,242 751 Others 2,743 6,633 Total 124,908 180,881 (1) Represented the prepaid expenses for telecommunications, network, online live steaming, advertising and student academic registration fee. ( 2 ) Represented rental deposits, deposits for search engine marketing activities and deposits for leasehold improvement of buildings which all being refundable within one year.

Deferred Costs (Tables)

Deferred Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Movement of Deferred Costs	The movements of deferred costs for the years ended December 31, 2018 and 2019 are as follows: As of December 31, 2018 2019 RMB RMB Beginning balances (current and non-current) 98,260 327,267 Additions 374,594 440,495 Amortizations (145,488 ) (318,693 ) Impairments (99 ) (134 ) Ending balances (current and non-current) 327,267 448,935 Deferred costs, current 180,657 243,447 Deferred costs, non-current 146,610 205,488

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Summary of Property and Equipment Consisted	Property and equipment consisted of the following: As of December 31, 2018 2019 RMB RMB Leasehold and buildings improvements 91,265 106,377 Electronic and office equipment 29,936 35,049 Buildings (1) 480,271 480,271 Total cost 601,472 621,697 Less: Accumulated depreciation (41,961 ) (76,022 ) Property and equipment, net 559,511 545,675 (1) In 2017, the Group purchased two buildings in Wuhan (Building A and B) and one building in Guangzhou (Building C) with a total consideration of RMB480,271. RMB60,000 of the consideration was paid by a mortgage loan provided by a PRC bank in August 2018 (Note 12).

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Intangible Assets Net Excluding Goodwill [Abstract]
Summary of Intangible Assets	The balance of intangible assets consisted of the following: As of December 31, 2018 2019 RMB RMB Computer software 3,757 3,757 License — 780 Less: Accumulated amortization (2,388 ) (3,361 ) Intangible assets, net 1,369 1,176
Summary of Amortization Expenses of Intangible Assets	The intangible assets amortization expenses for each of the following fiscal years are as follows: Amortization RMB 2020 479 2021 255 2022 156 2023 156 2024 130 Total 1,176

Other Non-Current Assets (Table

Other Non-Current Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Other Non-Current Assets	Other non-current assets consisted of the following: As of December 31, 2018 2019 RMB RMB Prepayment to acquire a building (1) 404,725 404,725 Employee loans (2) — 32,385 Rental deposits (3) 12,772 9,326 Others 1,203 1,203 Total 418,700 447,639 (1) The amount represented the prepayment for a building (Building D) in Wuhan and the building remained under construction by the real estate developer as of December 31, 2019. RMB200,000 of the prepayment was made through a mortgage loan provided by a PRC bank in November 2018 (Note 12). (2) In 2019, the Group approved an employee benefit program under which eligible employees can apply for loans from the Group at prevailing interest rates. Upon maturity, the loans can be repaid by cash or the Company's ordinary shares held by those employees based on prevailing market price at the settlement date. (3) The amount represented office and enrollment centers’ rental deposits under the lease contracts, which are not refundable within one year.

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Liabilities	The components of accrued expenses and other liabilities are as follows: As of December 31, 2018 2019 RMB RMB Refund liability (1) 6,625 128,478 Salary and welfare payables 124,137 113,945 Accrued service fees (2) 94,789 69,932 Accrued marketing expenses 120,269 51,796 Accrued rental expenses 51,087 — Payables to educational institutions (3) 6,024 23,071 Other tax liabilities 29,872 15,263 Advanced deposits (4) 6,650 11,681 Payables for leasehold improvement and intangible assets 4,911 6,818 American Depositary Receipt commission - within one year 3,482 3,526 Payables for share repurchase 857 — Other payables 6,581 10,715 455,284 435,225 (1 ) Refund liability represented the estimated amounts of deferred revenue with contingency in cash refund. (2) The balance represented accrued expenses for outsourced service providers and other professional services. (3 ) The balance represented tuition fees collected from the students for their registrations with educational institutions. (4) Advanced deposits primarily included down payments paid by prospective students before contracts signing.

Revenues and Deferred Revenue (

Revenues and Deferred Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Disaggregation Of Revenue [Abstract]
Schedule of Disaggregation of Revenue	disaggregated revenues by types were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Disaggregation of revenues Revenue by types: Gross revenues: Degree- or diploma-oriented post-secondary courses 822,832 1,814,178 2,021,990 Professional certification preparation and professional skills courses 145,840 161,366 155,370 Subtotal Online educational courses 968,672 1,975,544 2,177,360 Commissions 4,105 6,374 15,381 Others 1,901 587 8,100 Total revenues 974,678 1,982,505 2,200,841 Less: sales tax and surcharges (4,516 ) (8,520 ) (6,939 ) Total net revenues 970,162 1,973,985 2,193,902
Schedule of Movements of the Deferred Revenue	The movements of the deferred revenue for the years ended December 31, 2018 and 2019 were as follows (1) As of December 31, 2018 2019 RMB RMB Beginning balance (current and noncurrent) 2,110,428 3,286,025 Additions 3,214,400 2,236,638 Deductions (2,038,803 ) (2,293,893 ) Ending balance (current and noncurrent) 3,286,025 3,228,770 Deferred revenue, current 1,765,085 1,670,076 Deferred revenue, non-current 1,520,940 1,558,694 (1) Amounts presented are inclusive of VAT (see VAT in Note 2) .

Share Incentive Plan (Tables)

Share Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Option Activities and Changes	1 5 . SHARE INCENTIVE PLAN - continued Scheme II - continued A summary of option activities and changes during the year ended December 31, 2019 were presented below: Weighted- average Weighted- Weighted- remaining Aggregated average Number of average contractual intrinsic grant date Share option shares exercise price term(years) value fair value RMB RMB RMB Outstanding, December 31, 2018 51,831 560.95 8.81 — 271.90 Forfeited (5,200 ) 560.95 — — 271.90 Outstanding, December 31, 2019 46,631 560.95 7.81 — 271.90
Schedule of Assumptions Used to Calculate Estimated Fair Value of Options	The Company calculated the estimated fair value of the options on the respective grant dates using the binomial option pricing model with the assistance from an independent valuation firm, with the following assumptions used. October 20, Grant Dates 2017 Risk-free interest rate 2.0%-2.4% Volatility 32%-45% Expected dividend yield 0% Exercise multiples 2.2-2.8 Exercise price 0.0312-560.95 Life of option (years) 0.53-10 Fair value of underlying ordinary share 565.80
Schedule of Share-based Compensation Expense Recognized	Scheme II - continued Total share-based compensation expense of share-based awards granted to employees, certain directors and management recognized for the years ended December 31, 2017, 2018 and 2019 were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Cost of revenues 19,244 314 317 Sales and marketing expenses 75,237 773 674 General and administrative expenses 194,282 2,764 1,979 288,763 3,851 2,970

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Summary of Operating Leases	Year ended December 31,2019 RMB Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 85,717 Right-of-use assets obtained in exchange for new lease obligations: Operating leases 126,099 Weighted average remaining lease term Operating leases 12.2 years Weighted average discount rate Operating leases 6.7%
Summary of Maturity Analysis of Annual Undiscounted Cash Flows for Lease Liabilities	The following is a maturity analysis of the annual undiscounted cash flows for lease liabilities as of December 31, 2019: RMB 2020 91,182 2021 75,342 2022 72,690 2023 72,576 2024 75,026 2025 and thereafter 587,588 Total future lease payments 974,404 Less: Imputed interest 317,922 Total lease liability balance 656,482
Schedule of Future Minimum Payments Under Non-Cancelable Operating Leases to Offices and Enrollment Centers	Future minimum payments under non-cancelable operating leases related to offices and enrollment centers consisted of the following at December 31, 2018: RMB 2019 110,796 2020 97,949 2021 90,347 2022 83,251 2023 and thereafter 698,995 1,081,338

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Effective Tax Rate and Statutory Income Tax Rate Applicable to PRC Operations	The reconciliation of the effective tax rate and the statutory income tax rate applicable to PRC operations is as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Loss before income tax expenses (913,824 ) (928,660 ) (392,589 ) Income tax expenses computed at applicable tax rates of 25% (228,456 ) (232,165 ) (98,147 ) Non-deductible and super deduction expenses (3,490 ) (8,013 ) (40,711 ) Effect of tax holidays and preferential tax rates 130,296 64,029 22,595 Change in valuation allowance 101,650 176,149 118,703 Income tax expenses — — 2,440
Schedule of Components of Deferred Income Tax	The components of deferred taxes are as follows As of December 31, 2018 2019 RMB RMB Deferred tax assets Accrued expenses 13,270 6,511 Advertising expenses carry-forwards 87,600 58,288 Net operating loss carry-forwards 285,018 525,305 Total deferred tax assets 385,888 590,104 Less: valuation allowance (385,888 ) (504,591 ) Deferred tax assets, net — 85,513 Deferred tax liabilities Deferred costs — (87,954 ) Total deferred tax liabilities — (87,954 )

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Calculation of Net Loss Per Share	The number of ordinary shares used in the calculation of net loss per share for the year ended December 31, 2017 reflected the Group's 2017 Reorganization as described in Note 1. As of December 31, 2017 2018 2019 RMB RMB RMB Numerator: Net loss attributable to Sunlands Technology Group used in basic and diluted net loss per share: Net loss attributable to ordinary shareholders (918,578 ) (927,022 ) (394,817 ) Denominator: Weighted average ordinary shares outstanding used in computing basic and diluted net loss per share 3,945,864 6,294,870 6,830,058 Net loss per share Basic and diluted (232.80 ) (147.27 ) (57.81 )

Related Party Transaction (Tabl

Related Party Transaction (Tables)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Schedule of Major Related Parties and Their Relationships with Group	(1) The table below sets forth the major related parties and their relationship with the Group. Name of related parties Relationship with the Group Shangde Jiaxun Entity controlled by the Founder and the CEO (Note 1)
Summary of Related Party Transactions	(2) The related party transactions were as follows: Years ended December 31, 2017 2018 2019 RMB RMB RMB Disposal of a subsidiary to a related party 1,000 — —

Organization and Basis of Pre_3

Organization and Basis of Presentation - Additional Information (Details) - CNY (¥) ¥ in Thousands	5 Months Ended
	Jul. 31, 2016	Dec. 31, 2019	Dec. 31, 2015	Mar. 31, 2012
Variable Interest Entity [Line Items]
Recognized reorganization value			¥ 49,359
Sale or purchase of assets or rights minimum amount		¥ 50
Option agreement maximum contract amount		50
Consolidated VIE assets		0
Consolidated VIE creditor		¥ 0
Beijing Shangzhi Jiaye Education Technology Co., Ltd
Variable Interest Entity [Line Items]
Percentage of voting equity interests acquired	100.00%
Cash consideration	¥ 293,644
Sunland Education Technology H K Limited
Variable Interest Entity [Line Items]
Ownership percentage by parent				100.00%
Wuhan Zhibo
Variable Interest Entity [Line Items]
Ownership percentage by parent		100.00%
Wuhan Zhibo | Minimum
Variable Interest Entity [Line Items]
Ownership percentage by parent		10.00%
Wuhan Zhibo | Maximum
Variable Interest Entity [Line Items]
Ownership percentage by parent		100.00%

Organization and Basis of Pre_4

Organization and Basis of Presentation - Summary of Subsidiaries VIEs and VIEs' Subsidiaries (Details)	12 Months Ended
	Dec. 31, 2019
Variable Interest Entity [Line Items]
Place of establishment	E9
Sunlands HK
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Oct. 6, 2015
Place of establishment	K3
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Investment holding
Wuhan Zhibo
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Aug. 2, 2017
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of technical consultation and services
Tianjin Sunlands
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Jul. 31, 2017
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of technical consultation and services
Wuhan Shangde Online Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Jun. 25, 2019
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Chengdu Xinketang Cultural Communication Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Nov. 4, 2019
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Sales of educational materials and books
Beijing Sunlands
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Sep. 27, 2013
Place of establishment	F4
Principal activities	Investment holding and provision of education services
Tianjin Shangde
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Mar. 21, 2018
Place of establishment	F4
Principal activities	Provision of education services
Beijing Shangzhi Jiaye Education Technology Co., Ltd
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Mar. 13, 2012
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Beijing Shangren Chongye Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Sep. 27, 2013
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Guangdong Shangde Online Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Oct. 15, 2013
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Guangzhou Youhe Self-study Training School
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	May 19, 2015
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Beijing Heikuaima Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Mar. 3, 2016
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Shanghai Shangchi Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Dec. 22, 2016
Place of establishment	F4
Percentage of direct or indirect economic ownership	90.00%
Principal activities	Provision of education services
Shanghai Shangchi Institute
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Sep. 1, 2017
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services
Guangzhou Shangzhi Side Education Technology Co., Ltd.
Variable Interest Entity [Line Items]
Date of establishment/ acquisition	Sep. 28, 2017
Place of establishment	F4
Percentage of direct or indirect economic ownership	100.00%
Principal activities	Provision of education services

Organization and Basis of Pre_5

Organization and Basis of Presentation - Summary Financial Information of VIEs and their Subsidiaries (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2019USD ($)
Variable Interest Entity [Line Items]
Cash and cash equivalents	¥ 1,402,226	¥ 1,248,810		$ 201,417
Short-term investments	217,640	1,028,564		31,262
Prepaid expenses and other current assets	180,881	124,908		25,982
Total current assets	2,044,194	2,582,939		293,630
Right-of-use assets	598,991	0		86,040
Total non-current assets	1,924,508	1,156,199		276,438
TOTAL ASSETS	3,968,702	3,739,138		570,068
Accrued expenses and other current liabilities (including accrued expenses and other current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB241,204 and RMB209,727 as of December 31, 2018 and 2019, respectively)	435,225	455,284		62,516
Deferred revenue, current (including deferred revenue, current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,765,085 and RMB1,162,938 as of December 31, 2018 and 2019, respectively)	1,670,076	1,765,085		239,891
Lease liabilities, current	40,236			5,780
Total current liabilities	2,239,577	2,314,409		321,695
Deferred revenue, non-current (including deferred revenue, non-current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,520,940 and RMB1,096,482 as of December 31, 2018 and 2019, respectively)	1,558,694	1,520,940		223,892
Lease liabilities, non-current	616,246			88,518
TOTAL LIABILITIES	4,707,065	4,078,121		$ 676,127
Net revenues	2,049,461	1,973,985	¥ 970,162
Net (loss)/income	590,728	393,063	(606,946)
Net cash generated from/(used in) operating activities	(480,084)	1,448,005	845,616
Net cash (used in)/generated from investing activities	522,104	(315,198)	(375,802)
Net cash (used in)/generated from financing activities		8,018	¥ (391,237)
VIEs
Variable Interest Entity [Line Items]
Cash and cash equivalents	69,539	80,371
Short-term investments	38,990	587,051
Prepaid expenses and other current assets	106,568	46,601
Total current assets	284,887	818,480
Right-of-use assets	340,302
Total non-current assets	776,783	377,856
TOTAL ASSETS	1,061,670	1,196,336
Accrued expenses and other current liabilities (including accrued expenses and other current liabilities of the consolidated VIEs without recourse to Sunlands Technology Group of RMB241,204 and RMB209,727 as of December 31, 2018 and 2019, respectively)	209,727	241,204
Deferred revenue, current (including deferred revenue, current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,765,085 and RMB1,162,938 as of December 31, 2018 and 2019, respectively)	1,162,938	1,765,085
Lease liabilities, current	22,659
Total current liabilities	1,395,324	2,006,289
Deferred revenue, non-current (including deferred revenue, non-current of the consolidated VIEs without recourse to Sunlands Technology Group of RMB1,520,940 and RMB1,096,482 as of December 31, 2018 and 2019, respectively)	1,096,482	1,520,940
Lease liabilities, non-current	358,467
TOTAL LIABILITIES	¥ 2,854,823	¥ 3,527,364

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details) ¥ in Thousands, $ in Thousands	Jun. 01, 2019	Dec. 31, 2019CNY (¥)PerformanceObligationCustomer$ / ¥	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2019USD ($)Customer$ / ¥	Jan. 01, 2019CNY (¥)
Significant Accounting Policies [Line Items]
Currency exchange rate, Renminbi ("RMB") to U.S. dollar | $ / ¥		6.9618			6.9618
Rate of VAT	3.00%	6.00%
Advertising expenses		¥ 937,145	¥ 983,012	¥ 499,294
Cash and cash equivalents available for conversion to foreign currency		¥ 259,612	¥ 157,103
Percentage of cash and cash equivalents available for conversion to foreign currency		18.50%	12.60%		18.50%
Right of use asset		¥ 598,991	¥ 0		$ 86,040
Operating lease liabilities		¥ 656,482
Topic 842
Significant Accounting Policies [Line Items]
Right of use asset						¥ 560,200
Operating lease liabilities						¥ 607,200
Total Net Revenues | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Number of Customers | Customer		0			0
Revenues from customers individually representing portion of total net revenues		10.00%
Other Income
Significant Accounting Policies [Line Items]
Government subsidies		¥ 14,692	¥ 28,688	¥ 3,223
Maximum
Significant Accounting Policies [Line Items]
Time for full refund of transaction price		24 hours
Time for refund of transaction price to undelivered courses		7 days
Term of repayment of principal installments on which interest expense and service fees payable		18 months
Minimum
Significant Accounting Policies [Line Items]
Term of repayment of principal installments on which interest expense and service fees payable		3 months
Degree- or Diploma-oriented Post-secondary Courses
Significant Accounting Policies [Line Items]
Weighted average service period		32 months
Professional Certification Preparation and Professional Skills Courses
Significant Accounting Policies [Line Items]
Weighted average service period		19 months
Online Education Service and Insurance Service [Member]
Significant Accounting Policies [Line Items]
Number of performance obligation | PerformanceObligation		2

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Buildings | Minimum
Property Plant And Equipment [Line Items]
Estimated useful life	36 years
Buildings | Maximum
Property Plant And Equipment [Line Items]
Estimated useful life	37 years
Leasehold and Buildings Improvements
Property Plant And Equipment [Line Items]
Estimated useful life	Shorter of lease term or expected useful life
Electronic and Office Equipment | Minimum
Property Plant And Equipment [Line Items]
Estimated useful life	3 years
Electronic and Office Equipment | Maximum
Property Plant And Equipment [Line Items]
Estimated useful life	5 years

Significant Accounting Polici_6

Significant Accounting Policies - Summary of Estimated Useful Lives of Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2019
Computer Software
Finite Lived Intangible Assets [Line Items]
Estimated useful life	3 years
License
Finite Lived Intangible Assets [Line Items]
Estimated useful life	5 years

Short-Term Investments - Schedu

Short-Term Investments - Schedule of Short-Term Investment (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Investments Debt And Equity Securities [Abstract]
Short-term investments	¥ 217,640	$ 31,262	¥ 1,028,564

Short-Term Investments - Additi

Short-Term Investments - Additional Information (Details) - CNY (¥)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Impairment loss on short-term investments	¥ 0	¥ 0	¥ 0

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) ¥ in Thousands, $ in Thousands		Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid and input VAT		¥ 120,376		¥ 58,234
Prepaid expenses	[1]	21,896		10,820
Prepaid marketing expenses		16,192		23,756
Deposits	[2]	8,929		4,595
Receivables from third-party payment platforms		4,367		3,886
Interest receivables		1,737		11,632
Staff advances		751		9,242
Others		6,633		2,743
Total		¥ 180,881	$ 25,982	¥ 124,908
[1]	Represented the prepaid expenses for telecommunications, network, online live steaming, advertising and student academic registration fee.
[2]	Represented rental deposits, deposits for search engine marketing activities and deposits for leasehold improvement of buildings which all being refundable within one year.

Deferred Costs - Schedule of Mo

Deferred Costs - Schedule of Movements of Deferred Costs (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2019USD ($)
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Beginning balances (current and non-current)	¥ 327,267	¥ 98,260
Additions	440,495	374,594
Amortizations	(318,693)	(145,488)
Impairments	(134)	(99)
Ending balances (current and non-current)	448,935	327,267
Deferred costs, current	243,447	180,657	$ 34,969
Deferred costs, non-current	¥ 205,488	¥ 146,610	$ 29,517

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment Consisted (Details) ¥ in Thousands, $ in Thousands		Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Property Plant And Equipment [Line Items]
Total cost		¥ 621,697		¥ 601,472
Less: Accumulated depreciation		(76,022)		(41,961)
Property and equipment, net		545,675	$ 78,381	559,511
Leasehold and Buildings Improvements
Property Plant And Equipment [Line Items]
Total cost		106,377		91,265
Electronic and Office Equipment
Property Plant And Equipment [Line Items]
Total cost		35,049		29,936
Buildings
Property Plant And Equipment [Line Items]
Total cost	[1]	¥ 480,271		¥ 480,271
[1]	In 2017, the Group purchased two buildings in Wuhan (Building A and B) and one building in Guangzhou (Building C) with a total consideration of RMB480,271. RMB60,000 of the consideration was paid by a mortgage loan provided by a PRC bank in August 2018 (Note 12).

Property and Equipment, Net -_2

Property and Equipment, Net - Summary of Property and Equipment Consisted (Parenthetical) (Details) ¥ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)Building
Mortgage Loan
Business Acquisition [Line Items]
Consideration paid to acquire buildings | ¥	¥ 60,000
Buildings
Business Acquisition [Line Items]
Buildings purchased under consideration | ¥		¥ 480,271
Wuhan
Business Acquisition [Line Items]
Number of buildings purchased | Building		2
Guangzhou
Business Acquisition [Line Items]
Number of buildings purchased | Building		1

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Depreciation expenses	¥ 36,250	¥ 24,930	¥ 7,333

Intangible Assets, Net - Summar

Intangible Assets, Net - Summary of Intangible Assets (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Finite Lived Intangible Assets [Line Items]
Less: Accumulated amortization	¥ (3,361)		¥ (2,388)
Intangible assets, net	1,176	$ 169	1,369
Computer Software
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	3,757		¥ 3,757
License
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	¥ 780

Intangible Assets, Net - Additi

Intangible Assets, Net - Additional Information (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Intangible Assets Net Excluding Goodwill [Abstract]
Amortization expenses	¥ 973	¥ 848	¥ 776

Intangible Assets, Net - Summ_2

Intangible Assets, Net - Summary of Amortization Expenses of Intangible Assets (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Intangible Assets Net Excluding Goodwill [Abstract]
2020	¥ 479
2021	255
2022	156
2023	156
2024	130
Intangible assets, net	¥ 1,176	$ 169	¥ 1,369

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)Investment	Dec. 31, 2019USD ($)Investment	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Schedule Of Equity Method Investments [Line Items]
(Loss) gain from equity method investments	¥ (136,000)	$ (20)	¥ 1,710,000	¥ (4,890,000)
Impairment loss | ¥	¥ 0		¥ 0
Limited Partnerships
Schedule Of Equity Method Investments [Line Items]
Number of investments | Investment	3	3

Other Non-Current Assets - Summ

Other Non-Current Assets - Summary of Other Non-Current Assets (Details) ¥ in Thousands, $ in Thousands		Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepayment to acquire a building	[1]	¥ 404,725		¥ 404,725
Employee loans	[2]	32,385
Rental deposits	[3]	9,326		12,772
Others		1,203		1,203
Total		¥ 447,639	$ 64,299	¥ 418,700
[1]	The amount represented the prepayment for a building (Building D) in Wuhan and the building remained under construction by the real estate developer as of December 31, 2019. RMB200,000 of the prepayment was made through a mortgage loan provided by a PRC bank in November 2018 (Note 12).
[2]	In 2019, the Group approved an employee benefit program under which eligible employees can apply for loans from the Group at prevailing interest rates. Upon maturity, the loans can be repaid by cash or the Company's ordinary shares held by those employees based on prevailing market price at the settlement date.
[3]	The amount represented office and enrollment centers’ rental deposits under the lease contracts, which are not refundable within one year.

Other Non-Current Assets - Su_2

Other Non-Current Assets - Summary of Other Non-Current Assets (Parenthetical) (Details) - CNY (¥) ¥ in Thousands		Dec. 31, 2019	Dec. 31, 2018	Nov. 30, 2018
Other Non Current Assets [Line Items]
Prepayment to acquire a building	[1]	¥ 404,725	¥ 404,725
Mortgage Loan | PRC Bank
Other Non Current Assets [Line Items]
Prepayment to acquire a building				¥ 200,000
[1]	The amount represented the prepayment for a building (Building D) in Wuhan and the building remained under construction by the real estate developer as of December 31, 2019. RMB200,000 of the prepayment was made through a mortgage loan provided by a PRC bank in November 2018 (Note 12).

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Liabilities (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)
Payables And Accruals [Abstract]
Refund liability	¥ 128,478		¥ 6,625
Salary and welfare payables	113,945		124,137
Accrued service fees	69,932		94,789
Accrued marketing expenses	51,796		120,269
Accrued rental expenses			51,087
Payables to educational institutions	23,071		6,024
Other tax liabilities	15,263		29,872
Advanced deposits	11,681		6,650
Payables for leasehold improvement and intangible assets	6,818		4,911
American Depositary Receipt commission - within one year	3,526		3,482
Payables for share repurchase			857
Other payables	10,715		6,581
Total	¥ 435,225	$ 62,516	¥ 455,284

Revenues and Deferred Revenue -

Revenues and Deferred Revenue - Schedule of Disaggregated Revenues (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Disaggregation Of Revenue [Line Items]
Total revenues	¥ 2,200,841		¥ 1,982,505	¥ 974,678
Less: sales tax and surcharges	(6,939)		(8,520)	(4,516)
Total net revenues	2,193,902	$ 315,134	1,973,985	970,162
Subtotal Online Educational Courses
Disaggregation Of Revenue [Line Items]
Total revenues	2,177,360		1,975,544	968,672
Degree- or Diploma-oriented Post-secondary Courses | Subtotal Online Educational Courses
Disaggregation Of Revenue [Line Items]
Total revenues	2,021,990		1,814,178	822,832
Professional Certification Preparation and Professional Skills Courses | Subtotal Online Educational Courses
Disaggregation Of Revenue [Line Items]
Total revenues	155,370		161,366	145,840
Commissions
Disaggregation Of Revenue [Line Items]
Total revenues	15,381		6,374	4,105
Other Revenue
Disaggregation Of Revenue [Line Items]
Total revenues	¥ 8,100		¥ 587	¥ 1,901

Revenues and Deferred Revenue_2

Revenues and Deferred Revenue - Schedule of Movement of the Deferred Revenue (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2019USD ($)
Disaggregation Of Revenue [Abstract]
Beginning balance (current and noncurrent)	¥ 3,286,025	¥ 2,110,428
Additions	2,236,638	3,214,400
Deductions	(2,293,893)	(2,038,803)
Ending balance (current and noncurrent)	3,228,770	3,286,025
Deferred revenue, current	1,670,076	1,765,085	$ 239,891
Deferred revenue, non-current	¥ 1,558,694	¥ 1,520,940	$ 223,892

Revenues and Deferred Revenue_3

Revenues and Deferred Revenue - Additional Information (Details) - CNY (¥) ¥ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Abstract]
Deferred revenue	¥ 3,228,770	¥ 3,286,025	¥ 2,110,428

Revenues and Deferred Revenue_4

Revenues and Deferred Revenue - Additional Information (Details1) ¥ in Thousands	Dec. 31, 2019CNY (¥)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Disaggregation Of Revenue [Line Items]
Recognized revenue of remaining performance obligation	¥ 1,670,076
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-01-01
Disaggregation Of Revenue [Line Items]
Recognized revenue of remaining performance obligation	¥ 1,199,727
Revenue, remaining performance obligation, expected timing of satisfaction, period	24 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Disaggregation Of Revenue [Line Items]
Recognized revenue of remaining performance obligation	¥ 358,967
Revenue, remaining performance obligation, expected timing of satisfaction, period

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Nov. 21, 2018CNY (¥)Loan	Aug. 29, 2018CNY (¥)Loan
Debt Instrument [Line Items]
Debt instrument, term	8 years
Mortgage Bank Loan | PRC Bank
Debt Instrument [Line Items]
Debt instrument number of loan agreement | Loan			2	2
Debt instrument, face amount			¥ 260,000	¥ 260,000
Debt instrument periodic payment description	The loans are secured by pledging Building A and Building D and are repaid in equal instalment every three months with maturity term in 8 years.
Debt instrument, interest rate	1.472%
Repayment of secured loans	¥ 32,500	¥ 1,875

Ordinary Shares - Additional In

Ordinary Shares - Additional Information (Details) ¥ / shares in Units, $ / shares in Units, ¥ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2018CNY (¥)Voteshares	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2019$ / shares	Dec. 31, 2018$ / shares	Aug. 29, 2018USD ($)	Sep. 18, 2015$ / sharesshares	Sep. 18, 2015¥ / sharesshares
Ordinary Shares [Line Items]
Ordinary shares, shares authorized							1,000,000,000	1,000,000,000
Ordinary shares, par value | (per share)							$ 0.00005	¥ 0.0003
Ordinary shares, shares issued							1	1
Proceeds from initial public offering, net of issuance cost of 80,128 | ¥	¥ 1,109,517		¥ 1,109,517
Stock issuance costs | ¥	¥ 80,128		¥ 80,128
Ordinary shares, shares outstanding	4,329,000
American Depository Shares
Ordinary Shares [Line Items]
Ordinary shares newly issued	16,478,275
Number of shares repurchased		1,297,363	1,127,055
Class A Ordinary Shares
Ordinary Shares [Line Items]
Ordinary shares, shares authorized		796,062,195	796,062,195
Ordinary shares, par value | $ / shares				$ 0.00005	$ 0.00005
Ordinary shares, shares issued		1,830,183	1,818,383
Ordinary shares newly issued	659,131		659,131
Common stock, voting right		Class A ordinary share is entitled to one vote
Number of vote each ordinary shares entitled | Vote	1
Ordinary shares, shares outstanding	63,714	1,728,006	1,773,301
Authorized amount under share repurchase program | $						$ 50,000
Number of shares repurchased		51,895	45,082
Stock Repurchased During Period, Value | ¥		¥ 30,793	¥ 34,828
Conversion of shares		6,600
Class B Ordinary Shares
Ordinary Shares [Line Items]
Ordinary shares, shares authorized		826,389	826,389
Ordinary shares, par value | $ / shares				0.00005	0.00005
Ordinary shares, shares issued		826,389	826,389
Common stock, voting right		Class B ordinary share is entitled to seven votes
Number of vote each ordinary shares entitled | Vote	7
Class of each ordinary shares convertible into class A ordinary shares	1
Ordinary shares, shares outstanding		826,389	826,389
Class C Ordinary Shares
Ordinary Shares [Line Items]
Ordinary shares, shares authorized		203,111,416	203,111,416
Ordinary shares, par value | $ / shares				$ 0.00005	$ 0.00005
Ordinary shares, shares issued		4,258,686	4,265,286
Common stock, voting right		Class C ordinary share is entitled to ten votes
Number of vote each ordinary shares entitled | Vote	10
Class of each ordinary shares convertible into class A ordinary shares	1
Ordinary shares, shares outstanding	4,265,286	4,258,686	4,265,286
Conversion of shares		(6,600)
Series A Convertible Redeemable Preferred Shares
Ordinary Shares [Line Items]
Preferred stock outstanding	954,274
Convertible redeemable preferred shares converted into ordinary share	954,274
Series B Convertible Redeemable Preferred Shares
Ordinary Shares [Line Items]
Preferred stock outstanding	826,389
Convertible redeemable preferred shares converted into ordinary share	826,389
Series B+ Convertible Redeemable Preferred Shares
Ordinary Shares [Line Items]
Preferred stock outstanding	141,264
Convertible redeemable preferred shares converted into ordinary share	141,264

Share Incentive Plan - Addition

Share Incentive Plan - Additional Information (Details)	Oct. 20, 2017$ / sharesshares	Oct. 20, 2017$ / shares¥ / sharesshares	Apr. 26, 2019CNY (¥)	Aug. 31, 2017shares	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)shares	Aug. 24, 2018shares	Oct. 31, 2017shares	Oct. 20, 2017¥ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense | ¥					¥ 2,970,000	¥ 3,851,000	¥ 288,763,000
Dividend payout ratio assumed					0.00%
Unrecognized share-based compensation expenses | ¥					¥ 7,421,000
Weighted average recognition period of unrecognized share-based compensation expenses					2 years 2 months 12 days
Directors and Management
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense | ¥							¥ 83,133,000
Additional Ordinary Share | Directors and Management
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued without consideration | shares				146,930
Additional Ordinary Share | Independent Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued in exchange for services | ¥			¥ 1,100,000
2017 Share Incentive Plan | Additional Ordinary Share
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares approved for grant | shares								345,503	483,846
Common Stock, Capital Shares Reserved for Future Issuance | shares								829,349
Scheme I
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted | shares	363,452	363,452
Exercise price | (per share)	$ 0.0047	$ 0.0047								¥ 0.0312
Number of shares exercised | shares							363,452
Allocated Share-based Compensation Expense | ¥							¥ 205,630,000
Scheme II
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted | shares	66,053	66,053
Allocated Share-based Compensation Expense | ¥						¥ 2,751,000	¥ 0
Exercise price | (per share)	$ 84.75	$ 560.95
Scheme II | Vested on First Anniversary Grand Date
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting percentage					10.00%
Scheme II | Vested on Over Next Three Years
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting percentage					20.00%
Scheme II | Vested on Third Anniversary of Company IPO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting percentage					30.00%
Scheme II | Vested on Fourth Anniversary of Company IPO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting percentage					40.00%

Share Incentive Plan - Summary

Share Incentive Plan - Summary of Option Activities and Changes (Details) - Employee Stock Option - ¥ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Outstanding beginning balance	51,831
Number of shares, Forfeited	(5,200)
Number of shares, Outstanding ending balance	46,631	51,831
Weighted-average exercise price, Outstanding beginning balance	¥ 560.95
Weighted-average exercise price, Forfeited	560.95
Weighted-average exercise price, Outstanding ending balance	¥ 560.95	¥ 560.95
Weighted-average remaining contractual term, Outstanding	7 years 9 months 21 days	8 years 9 months 21 days
Weighted average grant date fair value, Outstanding beginning balance	¥ 271.90
Weighted average grant date fair value, Forfeited	271.90
Weighted average grant date fair value, Outstanding ending balance	¥ 271.90	¥ 271.90

Share Incentive Plan - Schedule

Share Incentive Plan - Schedule of Assumptions Used to Calculate Estimated Fair Value of Options (Details) - Binomial Option Pricing Model	Oct. 20, 2017¥ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	2.00%
Risk-free interest rate, maximum	2.40%
Volatility, minimum	32.00%
Volatility, maximum	45.00%
Expected dividend yield	0.00%
Fair value of underlying ordinary share	¥ 565.80
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise multiples	2.2
Exercise price	¥ 0.0312
Life of option (years)	6 months 10 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise multiples	2.8
Exercise price	¥ 560.95
Life of option (years)	10 years

Share Incentive Plan - Schedu_2

Share Incentive Plan - Schedule of Share-based Compensation Expense Recognized (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	¥ 2,970	¥ 3,851	¥ 288,763
Cost of Revenues
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	317	314	19,244
Selling and Marketing Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	674	773	75,237
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	¥ 1,979	¥ 2,764	¥ 194,282

Leases - Additional Information

Leases - Additional Information (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease, lease not yet commenced, description	As of December 31, 2019, the Group did not have additional operating leases that have not yet commenced.
Finance lease, description	As of December 31, 2019, the Group had no long-term leases that were classified as a financing lease.
Total operating lease expenses	¥ 96,165
Total operating lease expense	¥ 96,165	¥ 107,331	¥ 65,214

Leases - Summary of Operating L

Leases - Summary of Operating Leases (Details) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities, Operating cash flows from operating leases	¥ 85,717
Operating leases, Right-of-use assets obtained in exchange for new lease obligations:	¥ 126,099
Operating leases, Weighted average remaining lease term	12 years 2 months 12 days
Operating leases, Weighted average discount rate	6.70%

Leases - Summary of Maturity An

Leases - Summary of Maturity Analysis of Annual Undiscounted Cash Flows for Lease Liabilities (Details) ¥ in Thousands	Dec. 31, 2019CNY (¥)
Leases [Abstract]
2020	¥ 91,182
2021	75,342
2022	72,690
2023	72,576
2024	75,026
2025 and thereafter	587,588
Total future lease payments	974,404
Less: Imputed interest	317,922
Total lease liability balance	¥ 656,482

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Non-Cancelable Operating Leases to Offices and Enrollment Centers (Details) ¥ in Thousands	Dec. 31, 2018CNY (¥)
Commitments And Contingencies Disclosure [Abstract]
2019	¥ 110,796
2020	97,949
2021	90,347
2022	83,251
2023 and thereafter	698,995
Operating leases, future minimum payments due, Total	¥ 1,081,338

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Income Taxes [Line Items]
Statutory income tax rate	25.00%	25.00%	25.00%	25.00%
Income tax expenses	¥ 2,440,000	$ 350	¥ 0	¥ 0
Income tax expenses if the tax holidays granted to Beijing Sunlands were not available	0
Uncertain tax positions	¥ 0		0	0
Income tax rate outside the PRC	25.00%	25.00%
Hong Kong
Income Taxes [Line Items]
Income tax expenses	¥ 0		0	0
Hong Kong | For the First 2 Million Profits
Income Taxes [Line Items]
Statutory income tax rate	8.25%	8.25%
Hong Kong | For the Remaining Profits
Income Taxes [Line Items]
Statutory income tax rate	16.50%	16.50%
China
Income Taxes [Line Items]
Statutory income tax rate	25.00%	25.00%
Deferred income tax expense	¥ 2,440,000		¥ 0	¥ 0
China | subsidiaries and the Variable Interest Entities
Income Taxes [Line Items]
Statutory income tax rate	25.00%	25.00%
Operating loss carryforwards	¥ 2,923,067
Expiration start date	Dec. 31, 2020	Dec. 31, 2020
Expiration end date	Dec. 31, 2029	Dec. 31, 2029
China | 2016 | Beijing Sunlands
Income Taxes [Line Items]
Preferential tax rate description	Beijing Sunlands was qualified as “high and new technology enterprise strongly supported by the State” (“HNTE”) and was accordingly entitled to a preferential tax rate of 15% from calendar years 2016 through 2021 and is expected to be subject to an EIT rate of 15% as long as it maintains its status as a HNTE.	Beijing Sunlands was qualified as “high and new technology enterprise strongly supported by the State” (“HNTE”) and was accordingly entitled to a preferential tax rate of 15% from calendar years 2016 through 2021 and is expected to be subject to an EIT rate of 15% as long as it maintains its status as a HNTE.
Preferential tax rate	15.00%	15.00%
Preferential tax exemption approved start year	2016	2016
Preferential tax exemption approved end year	2021	2021

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Effective Tax Rate and Statutory Income Tax Rate Applicable to PRC Operations (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Income Tax Disclosure [Abstract]
Loss before income tax expenses	¥ (392,589)		¥ (928,660)	¥ (913,824)
Income tax expenses computed at applicable tax rates of 25%	(98,147)		(232,165)	(228,456)
Non-deductible and super deduction expenses	(40,711)		(8,013)	(3,490)
Effect of tax holidays and preferential tax rates	22,595		64,029	130,296
Change in valuation allowance	118,703		176,149	101,650
Income tax expenses	¥ 2,440	$ 350	¥ 0	¥ 0

Income Taxes - Schedule of Re_2

Income Taxes - Schedule of Reconciliation of Effective Tax Rate and Statutory Income Tax Rate Applicable to PRC Operations (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory income tax rate	25.00%	25.00%	25.00%

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Deferred Income Tax (Details) - CNY (¥) ¥ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Accrued expenses	¥ 6,511	¥ 13,270
Advertising expenses carry-forwards	58,288	87,600
Net operating loss carry-forwards	525,305	285,018
Total deferred tax assets	590,104	385,888
Less: valuation allowance	(504,591)	¥ (385,888)
Deferred tax assets, net	85,513
Deferred tax liabilities
Deferred costs	(87,954)
Total deferred tax liabilities	¥ (87,954)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Calculation of Net Loss Per Share (Details) ¥ / shares in Units, $ / shares in Units, ¥ in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2019CNY (¥)¥ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018CNY (¥)¥ / sharesshares	Dec. 31, 2017CNY (¥)¥ / sharesshares
Net loss attributable to Sunlands Technology Group used in basic and diluted net loss per share:
Net loss attributable to ordinary shareholders		¥ (394,817)	$ (56,713)	¥ (927,022)	¥ (918,578)
Denominator:
Weighted average ordinary shares outstanding used in computing basic and diluted net loss per share	[1]	6,830,058	6,830,058	6,294,870	3,945,864
Net loss per share
Basic and diluted | (per share)		¥ (57.81)	$ (8.30)	¥ (147.27)	¥ (232.80)
[1]	Each 25 American depositary shares ("ADSs") represents one of the Company's Class A ordinary shares.

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	46,631	51,831
Series A Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share			954,274
Series B Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share			826,389
Series B+ Preferred Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share			141,264

Related Party Transaction - Sum

Related Party Transaction - Summary of Related Party Transactions (Details) ¥ in Thousands	Dec. 31, 2017CNY (¥)
Related Party Transactions [Abstract]
Disposal of a subsidiary to a related party	¥ 1,000

Related Party Transaction - Add

Related Party Transaction - Additional Information - (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017
Related Party Transaction [Line Items]
Disposal of a subsidiary to a related party	¥ 1,000
Shangde Jiaxun
Related Party Transaction [Line Items]
Disposal of a subsidiary to a related party		¥ 1,000
Gain on disposition of assets	¥ 178

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Details) ¥ in Thousands	Dec. 31, 2019CNY (¥)
Long-term Investments
Commitments And Contingencies Disclosure [Line Items]
Investment commitment amount	¥ 34,837

Segment Reporting - Additional

Segment Reporting - Additional Information (Details) - Segment	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Number of operating segments	1	1	1

Employee Defined Contribution_2

Employee Defined Contribution Plan - Additional Information (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Amounts expensed as incurred for employee defined contribution plan	¥ 182,132	¥ 228,376	¥ 164,775

Restricted Net Assets - Additio

Restricted Net Assets - Additional Information (Details) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)
Restricted Net Assets [Abstract]
Required minimum percentage of after-tax-profit allocated to general reserve	10.00%
Threshold percentage of general reserve of the registered capital	50.00%
Required minimum percentage of after-tax-profit allocated to statutory common reserve	10.00%
Threshold percentage of statutory common reserve of the registered capital, used as criteria of allocation requirement	50.00%
Amount of restricted paid-in-capital and statutory reserves	¥ 1,189,308

Financial Statement Schedule I

Financial Statement Schedule I - Condensed Financial Information of Parent Company Balance Sheets (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2016CNY (¥)
ASSETS
Cash and cash equivalents	¥ 1,402,226	$ 201,417	¥ 1,248,810
Short-term investments	217,640	31,262	1,028,564
Prepaid expenses and other current assets	180,881	25,982	124,908
Total current assets	2,044,194	293,630	2,582,939
Non-current assets
Other non-current assets	447,639	64,299	418,700
Total non-current assets	1,924,508	276,438	1,156,199
TOTAL ASSETS	3,968,702	570,068	3,739,138
Current liabilities
Accrued expenses and other current liabilities	435,225	62,516	455,284
Total current liabilities	2,239,577	321,695	2,314,409
Non-current liabilities
Other non-current liabilities	11,469	1,647	17,147
Total non-current liabilities	2,467,488	354,432	1,763,712
TOTAL LIABILITIES	4,707,065	676,127	4,078,121
SHAREHOLDERS’ DEFICIT
Additional paid-in capital	2,363,999	339,567	2,391,822
Accumulated other comprehensive income	142,435	20,460	118,827
Accumulated deficit	(3,244,587)	(466,056)	(2,849,770)
TOTAL SHAREHOLDERS’ DEFICIT	(738,363)	(106,059)	(338,983)	¥ (1,641,768)	¥ (888,955)
TOTAL LIABILITIES AND SHAREHOLDERS’ DEFICIT	3,968,702	570,068	3,739,138
Class B Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	0	0	0
Class A Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	1		1
Treasury stock	(30,793)		(34,828)
TOTAL SHAREHOLDERS’ DEFICIT	1		1
Class C Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	1		1
TOTAL SHAREHOLDERS’ DEFICIT	1		1
Parent Company
ASSETS
Cash and cash equivalents	1,125,048	161,603	1,086,521
Short-term investments	0	0	441,513
Prepaid expenses and other current assets	1,244	177	11,950
Amounts due from subsidiaries	1,093,781	157,112	695,194
Total current assets	2,220,073	318,892	2,235,178
Non-current assets
Other non-current assets	26,849	3,857	0
Total non-current assets	26,849	3,857	0
TOTAL ASSETS	2,246,922	322,749	2,235,178
Current liabilities
Accrued expenses and other current liabilities	6,942	997	6,268
Total current liabilities	6,942	997	6,268
Non-current liabilities
Investment in subsidiaries	2,970,297	426,656	2,556,801
Other non-current liabilities	7,834	1,125	11,228
Total non-current liabilities	2,978,131	427,781	2,568,029
TOTAL LIABILITIES	2,985,073	428,778	2,574,297
SHAREHOLDERS’ DEFICIT
Treasury stock	0	0	0
Additional paid-in capital	2,363,999	339,567	2,391,822
Accumulated other comprehensive income	142,435	20,460	118,827
Accumulated deficit	(3,244,587)	(466,056)	(2,849,770)
TOTAL SHAREHOLDERS’ DEFICIT	(738,151)	(106,029)	(339,119)
TOTAL LIABILITIES AND SHAREHOLDERS’ DEFICIT	2,246,922	322,749	2,235,178
Parent Company | Class B Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	0	0	0
Parent Company | Class A Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	1	0	1
Parent Company | Class C Ordinary Shares
SHAREHOLDERS’ DEFICIT
Ordinary shares	¥ 1	$ 0	¥ 1

Financial Statement Schedule _2

Financial Statement Schedule I - Condensed Financial Information of Parent Company Balance Sheets (Parenthetical) (Details)	Dec. 31, 2019$ / sharesshares	Dec. 31, 2018$ / sharesshares	Mar. 31, 2018shares	Sep. 18, 2015$ / sharesshares	Sep. 18, 2015¥ / sharesshares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | (per share)				$ 0.00005	¥ 0.0003
Ordinary shares, shares authorized				1,000,000,000	1,000,000,000
Ordinary shares, shares issued				1	1
Ordinary shares, shares outstanding			4,329,000
Class A Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	796,062,195	796,062,195
Ordinary shares, shares issued	1,830,183	1,818,383
Ordinary shares, shares outstanding	1,728,006	1,773,301	63,714
Class B Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	826,389	826,389
Ordinary shares, shares issued	826,389	826,389
Ordinary shares, shares outstanding	826,389	826,389
Class C Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	203,111,416	203,111,416
Ordinary shares, shares issued	4,258,686	4,265,286
Ordinary shares, shares outstanding	4,258,686	4,265,286	4,265,286
Parent Company | Class A Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	796,062,195	796,062,195
Ordinary shares, shares issued	1,830,183	1,818,383
Ordinary shares, shares outstanding	1,728,006	1,773,301
Parent Company | Class B Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	826,389	826,389
Ordinary shares, shares issued	826,389	826,389
Ordinary shares, shares outstanding	826,389	826,389
Parent Company | Class C Ordinary Shares
Condensed Financial Statements Captions [Line Items]
Ordinary shares, par value | $ / shares	$ 0.00005	$ 0.00005
Ordinary shares, shares authorized	203,111,416	203,111,416
Ordinary shares, shares issued	4,258,686	4,265,286
Ordinary shares, shares outstanding	4,258,686	4,265,286

Financial Statement Schedule _3

Financial Statement Schedule I - Condensed Financial Information of Parent Company Statements of Operations (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Cost of revenues	¥ (396,316)	$ (56,927)	¥ (330,376)	¥ (170,261)
Gross profit	1,797,586	258,207	1,643,609	799,901
Operating expenses
Sales and marketing expenses	(1,792,285)	(257,446)	(2,152,830)	(1,351,811)
General and administrative expenses	(363,307)	(52,186)	(443,691)	(342,906)
Total operating expenses	(2,257,309)	(324,243)	(2,672,543)	(1,727,579)
Loss from operations	(459,723)	(66,036)	(1,028,934)	(927,678)
Loss before income tax expenses	(392,589)	(56,393)	(928,660)	(913,824)
Income tax expenses	2,440	350	0	0
Net loss	(395,165)	(56,763)	(926,950)	(918,714)
Parent Company
Cost of revenues	(317)	(46)	(475)	(19,244)
Gross profit	(317)	(46)	(475)	(19,244)
Operating expenses
Sales and marketing expenses	(674)	(97)	(820)	(75,237)
General and administrative expenses	(22,850)	(3,282)	(15,335)	(194,878)
Total operating expenses	(23,524)	(3,379)	(16,155)	(270,115)
Loss from operations	(23,841)	(3,425)	(16,630)	(289,359)
Interest income	38,331	5,505	33,525	1,592
Loss before income tax expenses	14,490	2,080	16,895	(287,767)
Income tax expenses	0	0	0	0
Loss from investment in subsidiaries	(409,307)	(58,793)	(943,781)	(630,947)
Net loss	¥ (394,817)	$ (56,713)	¥ (926,886)	¥ (918,714)

Financial Statement Schedule _4

Financial Statement Schedule I - Condensed Financial Information of Parent Company Consolidated Statements of Comprehensive Loss (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Net loss	¥ (395,165)	$ (56,763)	¥ (926,950)	¥ (918,714)
Other comprehensive (loss)/income, net of tax effect of nil:
Change in cumulative foreign currency translation adjustments	23,608	3,391	127,586	(8,759)
Total comprehensive loss	(371,557)	(53,372)	(799,364)	(927,473)
Parent Company
Net loss	(394,817)	(56,713)	(926,886)	(918,714)
Other comprehensive (loss)/income, net of tax effect of nil:
Change in cumulative foreign currency translation adjustments	23,608	3,391	127,586	(8,759)
Total comprehensive loss	¥ (371,209)	$ (53,322)	¥ (799,300)	¥ (927,473)

Financial Statement Schedule _5

Financial Statement Schedule I - Condensed Financial Information of Parent Company Statements of Cash Flows (Details) ¥ in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2018CNY (¥)	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss		¥ (395,165)	$ (56,763)	¥ (926,950)	¥ (918,714)
Adjustments to reconcile net loss to net cash generated from operating activities:
Share-based compensation		2,970	427	3,851	288,763
Loss from investment in subsidiaries		136	20	(1,710)	4,890
Prepaid expenses and other current assets		(39,769)	(5,712)	(92,291)	(30,222)
Other non-current assets		3,446	495	(4,286)	(7,480)
Accrued expenses and other current liabilities		25,216	3,622	214,697	164,245
Net cash generated from/(used in) operating activities		(533,547)	(76,638)	180,543	819,538
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of short-term investments		(2,108,820)	(302,913)	(4,352,103)	(2,139,097)
Proceeds from maturity of short-term investments		2,905,788	417,390	3,708,810	1,931,027
Loan to employees		(33,085)	(4,752)
Net cash (used in) / generated from investing activities		729,546	104,794	(1,186,721)	(615,895)
CASH FLOWS FROM FINANCING ACTIVITIES
Amounts due from related parties				253,672	7,944
Proceeds from initial public offering, Net of issuance cost of 80,128	¥ 1,109,517			1,109,517
Capital contribution from Series B and B+ convertible redeemable preferred shareholders					732,709
Net cash generated from / (used in) financing activities		(64,150)	(9,214)	1,587,343	341,472
Effect of exchange rate changes		21,567	3,095	108,186	(8,759)
Net increase in cash and cash equivalents		153,416	22,037	689,351	536,356
Cash and cash equivalents at beginning of the year		1,248,810	179,380	559,459	23,103
Cash and cash equivalents at end of the year		1,402,226	201,417	1,248,810	559,459
Parent Company
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss		(394,817)	(56,713)	(926,886)	(918,714)
Adjustments to reconcile net loss to net cash generated from operating activities:
Share-based compensation		2,970	427	3,851	288,763
Loss from investment in subsidiaries		413,496	59,395	1,032,235	813,313
Amounts due to subsidiaries		(398,587)	(57,253)	(185,537)	(751,735)
Prepaid expenses and other current assets		18,032	2,594	(19,276)
Other non-current assets		(3,394)	(488)	11,228
Accrued expenses and other current liabilities		1,531	220	4,231	75
Net cash generated from/(used in) operating activities		(360,769)	(51,818)	(80,154)	(568,298)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of short-term investments				(814,539)
Proceeds from maturity of short-term investments		436,228	62,660	396,852
Loan to employees		(26,849)	(3,857)
Net cash (used in) / generated from investing activities		409,379	58,803	(417,687)
CASH FLOWS FROM FINANCING ACTIVITIES
Amounts due from related parties				245,654
Payment for share repurchase		(31,650)	(4,546)	(33,971)
Proceeds from initial public offering, Net of issuance cost of 80,128				1,109,517
Capital contribution from Series B and B+ convertible redeemable preferred shareholders					732,709
Net cash generated from / (used in) financing activities		(31,650)	(4,546)	1,321,200	732,709
Effect of exchange rate changes		21,567	3,095	107,510	(8,759)
Net increase in cash and cash equivalents		38,527	5,534	930,869	155,652
Cash and cash equivalents at beginning of the year		1,086,521	156,069	155,652
Cash and cash equivalents at end of the year		¥ 1,125,048	$ 161,603	¥ 1,086,521	¥ 155,652

Financial Statement Schedule _6

Financial Statement Schedule I - Condensed Financial Information of Parent Company Statements of Cash Flows (Parenthetical) (Details) - CNY (¥) ¥ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Statement Of Cash Flows [Abstract]
Net of issuance cost	¥ 80,128	¥ 80,128