As filed with the Securities and Exchange Commission on October 12, 1998
                                              Registration No. 33-___________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                ----------------

                                    FORM S-3
             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
                                ----------------

                            BOK FINANCIAL CORPORATION
             (Exact name of registrant as specified in its charter)

 Oklahoma                                                            73-1373454
 (State or other jurisdiction                                  (I.R.S. Employer
 incorporation or organization)                              Identification No.)

                             Bank of Oklahoma Tower
                         Boston Avenue at Second Street
                              Tulsa, Oklahoma 74172
                                 (918) 588-6000
                   (Address, including zip code, and telephone
              number, including area code of registrant's principal
                               executive offices)

                                 James A. White,
              Executive Vice President and Chief Financial Officer
                            BOK FINANCIAL CORPORATION
                             Bank of Oklahoma Tower
                         Boston Avenue at Second Street
                              Tulsa, Oklahoma 74172
                                 (918) 588-6416
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
                                 With copies to:
                                Frederic Dorwart
                                  Old City Hall
                             124 East Fourth Street
                              Tulsa, Oklahoma 74103
                                 (918) 583-9922
         Approximate date of commencement of proposed issuance to the public: As
soon as practicable after this Registration Statement becomes effective.
                               -------------------
         If any of the  securities  being  registered  on  this  Form  are to be
offered  on a  delayed  or  continuous  basis  pursuant  to Rule 415  under  the
Securities Act of 1933,  other than  securities  offered only in connection with
dividend or interest reinvestment plans, check the following box. [X]
                         CALCULATION OF REGISTRATION FEE

                                      Proposed         Proposed
                                       maximum          maximum
  Title of each       Amount          offering         aggregate      Amount of
class of securities     to be          price            offering    Registration
to be registered      registered 1/   per share 1/      price 1/        fee2/  
- --------------------------------------------------------------------------------
Debt Securities       $250,000,000      100% (1)     $250,000,000      $73,750

1/ There are being registered  hereunder such indeterminate  principal amount of
Senior Debt Securities as shall have an aggregate  initial offering price not to
exceed  $250,000,000.  The proposed maximum initial offering price per unit will
be determined, from time to time, by the Company in connection with the issuance
by the Company of the Securities registered hereunder. 

2/  Calculated  pursuant to Rule 457(o) of the rules and  regulations  under the
Securities Act of 1933.

================================================================================
    The  Registrant  hereby amends this  Registration  Statement on such date or
dates as may be necessary to delay its effective date until the Registrant shall
file a further  amendment  which  specifically  states  that  this  Registration
Statement shall  thereafter  become effective in accordance with Section 8(a) of
the  Securities  Act of 1933 or until the  Registration  Statement  shall become
effective on such date as the Commission,  acting pursuant to said Section 8(a),
may determine.

                                                       
i

                                                           
                            BOK FINANCIAL CORPORATION

         Cross  Reference  Sheet Showing  Location in Prospectus of  Information
Required to be included in Prospectus in Response to Items of Form S-3, Pursuant
to Item 501 of Regulation S-K.

Item #  Form S-3 Item                                   Caption in Prospectus

   1. Forepart of Registration Statement
      and Outside Front Cover of Prospectus...........Forepart and Outside Front
                                                      Cover

   2. Inside Front and Outside Back
      Cover Pages of Prospectus.......................Inside Front and Outside
                                                      Back Cover Pages;
                                                      Table of Contents

   3. Summary Information, Risk Factors
      and Ratio of Earnings to Fixed Charges..........Summary Information 
                                                      Respecting BOK Financial
                                                      Corporation; Risk Factors;
                                                      Ratio of Earnings
                                                      to Fixed Charges

   4. Use of Proceeds.................................Use of Proceeds

   5. Determination of Offering Price.................Outside Front Cover Page; 
                                                      Plan of  Distribution

   6. Dilution........................................Not Applicable

   7. Selling Security Holders........................Not Applicable

   8. Description of Securities to be Registered......Description of Senior Debt
                                                      Securities

   9. Plan of Distribution............................Plan of Distribution

   10.Interest of Named Experts and Counsel...........Legal Opinions; Experts

   11.Material Changes................................Not Applicable

   12.Incorporation of Certain
      Information by Reference........................Where You Can Find More 
                                                      Information

   13.Disclosure of Commission Position on
      Indemnification for Securities Act Liabilities..Not Applicable;See,Part II

                                                       
ii

                                                                         
                  SUBJECT TO COMPLETION; PRELIMINARY PROSPECTUS
                            DATED OCTOBER 12, 1998
                            BOK FINANCIAL CORPORATION
                                     Issuer
   [BOKF LOGO]         $250,000,000 Senior Debt Securities

- --------------------------------------------------------------------------------
Consider carefully the risk factors beginning on page 5 in this prospectus.
- --------------------------------------------------------------------------------

The Debt  Securities  will not be deposits and are not insured or  guaranteed by
the Federal Deposit Insurance Corporation or any other governmental agency.

The securities do not represent the obligations of any bank.

This  prospectus may be used to offer and sell any series of securities  only if
accompanied by the prospectus supplement for that series.
BOK Financial Corporation will:

         **   issue one or more series of Senior Debt Securities

         **   in the form of debentures, notes, or other unsecured
              evidences of indebtedness

         **   in an amount not to exceed a total of $250,000,000

         **   in definitive or global form

A  prospectus  supplement  will  further  define the Senior Debt  Securities  by
stating:

         **   how the Senior Debt Securities will be sold

         **   the initial offering price

         **   the number of Senior Debt Securities being offered

          **  the names of any underwriters and agents and their compensation

          **  the net proceeds to BOK Financial of the sale

          **  the use BOK Financial will make of the proceeds

          **  the   terms  of  the   Senior   Debt Securities  including  the 
              interest rates, maturities, redemption rights, puts and other 
              features

                           ---------------------------

     NEITHER THE  SECURITIES AND EXCHANGE  COMMISSION  NOR ANY STATE  SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE  SECURITIES,  OR PASSED UPON THE
ADEQUACY OR ACCURACY OF THE PROSPECTUS.  ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE. 

                          ----------------------------
          The  common  stock of BOK  Financial  is  listed on the  NASDAQ  Stock
Exchange under the trading  symbol  "BOKF".  BOK Financial does not plan to list
the Senior Debt Securities on NASDAQ or any other exchange.

                                                        

iii


                                TABLE OF CONTENTS
                                                                     Page

ABOUT THIS PROSPECTUS................................................1

WHERE YOU CAN FIND MORE INFORMATION..................................1

SUMMARY INFORMATION RESPECTING BOK FINANCIAL CORPORATION.............2

RISK FACTORS.........................................................3

DESCRIPTION OF SENIOR DEBT SECURITIES................................6

GLOBAL SECURITIES....................................................15

USE OF PROCEEDS......................................................17

PLAN OF DISTRIBUTION.................................................18

RATIO OF EARNINGS TO FIXED CHARGES...................................19

VALIDITY OF THE SENIOR DEBT SECURITIES...............................19

EXPERTS..............................................................19


                                                       

1

                              ABOUT THIS PROSPECTUS

     This prospectus is part of a registration  statement that we filed with the
SEC utilizing a "shelf" registration  process.  Under this shelf process, we may
sell any  combination of the securities  described in this  prospectus in one or
more  offerings up to a total dollar  amount of  $250,000,000.  This  prospectus
provides you with a general  description  of the  securities we may offer.  Each
time we sell  securities,  we will  provide a  prospectus  supplement  that will
contain specific  information  about the terms of that offering.  The prospectus
supplement  may  also  add,  update  or  change  information  contained  in this
prospectus.  You should read both this prospectus and any prospectus  supplement
together with additional  information described under the heading "WHERE YOU CAN
FIND MORE INFORMATION."

       We are  complying  with  the  SEC's  plain  English  program.  This is an
initiative  launched by the SEC to make  prospectuses and other information more
understandable to the general investor.  To see more detail, you should read the
exhibits filed with this registration statement.

                       WHERE YOU CAN FIND MORE INFORMATION

         We file annual,  quarterly and special  reports,  proxy  statements and
other  information  with the SEC.  You may read and copy any document we file at
the SEC's  public  reference  rooms at Room  1024,  Judiciary  Plaza,  450 Fifth
Street,  N.W.,  Washington,  D.C.  20549,  and at the SEC's Fort Worth  Regional
Offices at 503 U. S.  Courthouse,  10th and Lamar  Streets,  Forth Worth,  Texas
76102 and at Listing Company Information, NASDAQ Stock Exchange, 9801 Washington
Blvd.,  Gaithersburg,  Maryland 20878.  You may send for a copy of such material
for a fee by writing the Securities  and Exchange  Commission  Public  Reference
Section,  Room 1024, 450 Fifth Street,  N.W.,  Washington,  D.C. 20549.  Our SEC
filings are also available to the public over the Internet at the SEC's web site
at  http://www.sec.gov.  Please  call  the  SEC at  1-800-SEC-0330  for  further
information on the public reference rooms and Internet access.

         The SEC allows us to "incorporate by reference" the information we file
with them,  which means that we can  disclose  important  information  to you by
referring you to those documents.  The information  incorporated by reference is
an important part of this  prospectus,  and information  that we file later with
the SEC will automatically update and supersede this information. We incorporate
by reference the documents listed below and any future filings made with the SEC
under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934
until we sell all of the securities.

          **   Annual  Report of the  Company on Form 10-K for the  fiscal  year
               ended December 31, 1997; and

          **   Quarterly Report on Form 10-Q for the fiscal quarters ended March
               31, 1998 and June 30, 1998.

You may request a copy of these filings at no cost, by writing or telephoning us
at the following address:

                                                       

2


         Chief Financial Officer
         BOK Financial Corporation
         Bank of Oklahoma Tower
         Tulsa, Oklahoma 74172
         (918) 588-6752
         inquire@mail.bokf.com

         You should rely only on the  information  incorporated  by reference or
provided in this prospectus or any prospectus supplement. We have not authorized
anyone  else to provide  you with  different  information.  We are not making an
offer of these  securities  in any state where the offer is not  permitted.  You
should not assume that the  information  in this  prospectus  or any  prospectus
supplement  is accurate as of any date other than the date on the front of those
documents.

                               SUMMARY INFORMATION
                                   RESPECTING
                            BOK FINANCIAL CORPORATION

          **   Our home office is Tulsa, Oklahoma

          **   Our principal  subsidiaries  are Bank of Oklahoma  N.A.,  Bank of
               Texas  N.A.,  Bank of  Arkansas  N.A.,  BOSC,  Inc,  BOK  Capital
               Services Corporation, and Bank of Texas Trust Company, N.A.

          **   We have a total of 2,448 employees

          **   We offer commercial,  consumer and correspondent banking services
               and investment and money market services

          **   Our BOk Trust Division  offers trust services,  employee  benefit
               services, investment advice, and asset management

          **   Our BOk  Mortgage  Division  originates  and  services  home loan
               mortgages

          **   Our BOSC  subsidiary is a registered NASD  broker-dealer  with 91
               sales representatives

          **   The Leo Oppenheim Division of BOSC underwrites  municipal revenue
               bonds,  asset-backed  securities,  and  commercial  paper and has
               eight investment bankers and sales representatives

          **   Approximately 92 percent of our earnings are derived from Bank of
               Oklahoma

                                                       

3


          **   Bank of Oklahoma is headquartered  in Oklahoma,  has 62 locations
               in Oklahoma, 2,302 employees, and approximately $3,486,957,000 in
               deposits.

          **   Bank of Texas is  headquartered  in  Dallas,  Texas  and has five
               locations,  131  employees,  and  approximately  $371,889,000  in
               deposits.

          **   Bank of Arkansas is headquartered  in Fayetteville,  Arkansas and
               has four locations, 36 employees,  and approximately  $86,011,000
               in deposits.

          **   We have agreed, subject to regulatory approval, to organize a new
               New Mexico national bank to be headquartered in Albuquerque,  New
               Mexico and called Bank of Albuquerque, with 17 bank branches, 230
               employees, and approximately $500 million in deposits.

          **   We expect to close the New Mexico transaction in December, 1998.

                                  RISK FACTORS

THE SENIOR DEBT SECURITIES INVOLVE A RISK OF LOSS OF PRINCIPAL AND INTEREST. YOU
SHOULD  CONSIDER THE FOLLOWING RISK FACTORS IN DECIDING  WHETHER TO PURCHASE THE
SENIOR DEBT SECURITIES.

Risk of Competition

          **   The banking industry is increasingly competitive

          **   In   particular,   the  Oklahoma   banking   industry  is  highly
               competitive  and  approximately  92% of our  earnings are derived
               from Bank of Oklahoma

          **   In 1997,  NationsBank  (now Bank America) and BancOne entered the
               Oklahoma market

          **   We have to compete with numerous other small and large, local and
               national  savings and loan  associations,  banks,  credit unions,
               trust companies, broker-dealers, and underwriters

Risk of Supervision and Regulation

          **   We and our subsidiaries are extensively regulated under both
                  federal and state law,  particularly  the Bank Holding Company
                  Act of 1956 and the National Bank Act

                                                       

4


          **   We are limited to the business of banking and related  businesses
               which   prohibits  us  from   expanding  into  certain  types  of
               businesses which could be profitable for us

          **   Where we can do business and establish offices is regulated which
               could decrease our ability to expand into new markets

          **   The  amount of  deposits  we can own in each  state is  regulated
               which limits our potential growth

          **   Our ability to make  acquisitions  and engage in new business may
               be  limited  by the  performance  of our  obligations  under  the
               Community  Reinvestment  Act to provide services in traditionally
               underserved areas

          **   We do not know the extent to which  changes in the  statutes  and
               regulations  under we operate may  adversely  affect our business
               and we do not have control over such changes

          **   Those of our  competitors  which  are not banks  are  subject  to
               significantly  less  government  regulation than we are which may
               give them a competitive advantage in the market place

Risk of Regulatory Limitations on Payment of Dividends

          **   Our  earnings  will be the  source  of our  ability  to repay the
               Senior Debt Securities

          **   Because  we  are  a  bank  holding  company,   our  earnings  are
               principally derived from dividends from our banks

          **   Regulations of the  Comptroller of the Currency limit the ability
               of our banks to pay us dividends by requiring that a bank receive
               approval of the OCC before  declaring a dividend if the amount of
               all  dividends,  including the proposed  dividend,  declared by a
               bank in any calendar year exceeds:

               (1)  the total of the bank's net profits of that calendar year to
                    date plus

               (2)  retained net profits of the preceding two years minus

               (3)  any  required  transfers  to  surplus  or  a  fund  for  the
                    retirement of preferred stock

                                                       

5


Risk of Capital Requirements

          **   The Federal Deposit Insurance Improvement Act of 1991 established
               five  capital  rating  tiers  ranging  from well  capitalized  to
               critically undercapitalized

          **   We must maintain capital ratios above the well capitalized  level
               if we want to  experience  significant  growth and acquire  other
               financial institutions and branches

          **   Well capitalized means a minimum of 5% for Leverage  Capital,  6%
               for Tier I Capital, and 10% for Total Capital

          **   At June 30, 1998, our ratios were 7.24% for Leverage Capital,
                  9.35% for Tier I Capital, and 14.15% for Total Capital

          **   At June 30, 1998, our  subsidiary  banks were also well above the
               required minimum leverage and risk-based  ratios,  but if we fall
               below these ratios, the growth potential of our business would be
               limited

Risk of Government Policies and Economic Factors

Our business is highly sensitive to:

          **   changes in legislation  and the policies and  examinations of the
               various regulatory authorities

          **   the monetary  policies  implemented by the Federal Reserve Board,
               including  the discount  rate on bank  borrowings  and changes in
               reserve  requirements which affects our ability to make loans and
               the interest rates we may charge

          **   open market operations in U.S. Government securities

          **   changes in prevailing interest rates because of the dependency of
               our banks on
                  interest income

          **   We cannot  predict the effect of such matters on our business and
               earnings

Risk of Lack of Marketability

          **   We cannot  guarantee  a  secondary  market  for our  Senior  Debt
               Securities  or that  holders  who wish to sell their  Senior Debt
               Securities prior to the stated maturity will be able to do so

                                                       

6


          **   We do not plan to list the Senior Debt  Securities for trading on
               any exchange or other trading market

Risk of Year 2000 Problems

          **   We, and our  service  providers,  are having to modify or replace
               significant  portions  of our and  their  computer  software  and
               hardware to ensure that our systems  will  function  correctly in
               the Year 2000 and thereafter

          **   We have made good  progress  and do not foresee  any  significant
               operational  problems  with our  systems or those of our  service
               providers;  however, if we or our service providers do not timely
               complete the required  modifications and  replacements,  we could
               experience a material adverse impact on our business and earnings

                      DESCRIPTION OF SENIOR DEBT SECURITIES

         This  description of the Senior Debt  Securities does not purport to be
complete and is subject to, and  qualified in its entirety by reference  to, the
indentures  pursuant to which such Senior Debt Securities are issued,  the forms
of which indentures are filed as exhibits to the registration statement of which
this prospectus is a part. Furthermore, the following summary description of the
indentures  and  the  Senior  Debt  Securities  relates  to  certain  terms  and
conditions  applicable to the Senior Debt Securities  generally.  The particular
terms  of any  series  of  Senior  Debt  Securities  will  be  described  in the
applicable prospectus supplement. If so indicated in such prospectus supplement,
the terms of any such series may differ from the terms set forth below.

         General

         Senior  Debt  Securities  are to be  issued  under  an  indenture  (the
"Indenture")  between BOK  Financial  Corporation  and the trustee  named in the
applicable  prospectus  supplement as the trustee therefor (the "Trustee").  The
form of  Indenture  is an exhibit to the  registration  statement  of which this
prospectus is a part.

         The Senior Debt Securities will be direct, unsecured obligations of BOK
Financial Corporation.  The Senior Debt Securities will not be deposits or other
obligations  of a bank and will not be  guaranteed or insured by the FDIC or any
other governmental agency.

                                                       

7


         The Indenture does not limit the aggregate  principal  amount of Senior
Debt  Securities or of any particular  series of Senior Debt Securities that may
be issued  thereunder and provide that Senior Debt Securities  issued thereunder
may be  issued  from time to time in one or more  series,  in each case with the
same or various  maturities,  at par or at a discount.  The  Indenture  does not
limit the amount of other debt that may be issued by BOK  Financial  Corporation
and does not contain financial or similar restrictive  covenants.  The Indenture
does not prohibit or limit the incurrence of additional  senior  indebtedness or
other financial obligations.  The Indenture provides that there may be more than
one Trustee under such Indenture with respect to different series of Senior Debt
Securities.

         The  Indenture  does not  contain  any  provision  intended  to provide
protection  to holders of Senior  Debt  Securities  against a sudden or dramatic
decline in credit quality of BOK Financial  Corporation that could, for example,
result   from  a   takeover,   recapitalization,   special   dividend  or  other
restructuring.

         The applicable  prospectus supplement will describe the following terms
of the series of Senior Debt  Securities in respect of which this  prospectus is
being delivered:

         (1)      the title of such Senior Debt Securities;

         (2)      any limit upon the aggregate  principal  amount of such Senior
                  Debt Securities and the percentage of such principal amount at
                  which such Senior Debt Securities may be issued;

         (3)      the date or dates on which the  principal  of such Senior Debt
                  Securities  is  scheduled  to  become   payable  (the  "Stated
                  Maturity");

         (4)      the rate or rates (which may be fixed or  variable)  per annum
                  at which such Senior Debt  Securities  will bear interest,  or
                  the method of determining such rate or rates, if any, the date
                  or dates from which any such interest  will accrue,  the dates
                  on which any such  interest  will be  payable  (the  "Interest
                  Payment  Dates"),  the Regular  Record Date (as defined in the
                  Indenture)  for the interest  payable on any Interest  Payment
                  Date, and the person to whom principal of or premium,  if any,
                  or interest on any Senior Debt Security of such series will be
                  payable,  if other than the  person in whose name such  Senior
                  Debt  Security  (or  one  or  more  predecessor   Senior  Debt
                  Securities)  is  registered  at the close of  business  on the
                  Regular Record Date for such interest;

         (5)      if other than the location  specified in this prospectus,  the
                  place or places where the  principal  of and premium,  if any,
                  and interest on Senior Debt Securities will be payable;

         (6)      the period or  periods  within  which,  the price or prices at
                  which and the terms and conditions upon which such Senior Debt
                  Securities  will,  pursuant  to  any  mandatory  sinking  fund
                  provisions  or  otherwise,  or may,  pursuant to any  optional
                  sinking fund provisions or otherwise,  be redeemed in whole or
                  in part by BOK Financial Corporation;

         (7)      the period or  periods  within  which,  the price or prices at
                  which and the terms and conditions upon which such Senior Debt
                  Securities  may be repaid,  in whole or in part, at the option
                  of the holders thereof;

                                                       
8


         (8)      if  other  than  denominations  of  $1,000  and  any  integral
                  multiple thereof,  the denominations in which such Senior Debt
                  Securities will be issuable;

         (9)      if other than the principal amount thereof, the portion of the
                  principal  amount of such Senior Debt  Securities that will be
                  payable  upon  declaration  of  acceleration  of the  maturity
                  thereof;

         (10)     the  currency or currency  unit of payment of principal of and
                  premium,  if any, and interest on such Senior Debt Securities,
                  and any index used to determine  the amount of principal of or
                  premium, if any, and interest on such Senior Debt Securities;

         (11)     whether  such  Senior  Debt  Securities  are to be issuable as
                  Global  Securities  (as defined  below) and, in such case, the
                  initial  securities  depositary  with respect  thereto and the
                  circumstances   under  which  such  Global   Security  may  be
                  exchanged for definitive securities; and

         (12) any other material terms of such Senior Debt Securities.

         Form, Registration and Transfer

         Unless  otherwise  indicated in the applicable  prospectus  supplement,
principal  of,  and  premium,  if any,  and  interest,  if any,  on Senior  Debt
Securities will be payable, and Senior Debt Securities will be transferable,  at
the agency or office of BOK Financial Corporation maintained for such purpose in
the Borough of Manhattan, The City of New York, except that interest may be paid
at the option of BOK Financial Corporation by check mailed to the address of the
holder entitled  thereto as it appears on the applicable  Security  Register (as
defined in the applicable Indenture).

         Unless  otherwise  indicated in the applicable  prospectus  supplement,
Senior Debt Securities  will be issued only in fully  registered  form,  without
coupons,  in  denominations  of $1,000 and any integral  multiple  thereof.  The
Indentures  provide that Senior Debt Securities of any series may be issuable in
permanent global form. See "GLOBAL  SECURITIES" below. No service charge will be
made for any registration of transfer or exchange of the Senior Debt Securities,
but BOK Financial  Corporation  may require payment of a sum sufficient to cover
any tax or other governmental charge payable in connection therewith.

         Limitation on Disposition of Voting Stock of Principal Subsidiary Banks


                                                       
9


         The Indenture contains a covenant by BOK Financial  Corporation that it
will not sell,  assign,  transfer,  grant a security  interest  in or  otherwise
dispose of any shares of,  securities  convertible into or options,  warrants or
rights to subscribe for or purchase  shares of, Voting Stock (as defined  below)
(other than directors'  qualifying shares) of any Principal  Subsidiary Bank (as
defined  below)  and that it will not permit any  Principal  Subsidiary  Bank to
issue  (except  to  BOK  Financial   Corporation)  any  shares  of,   securities
convertible  into,  or options,  warrants or rights to subscribe for or purchase
shares of,  Voting Stock of any  Principal  Subsidiary  Bank,  except for sales,
assignments, transfers, grants of security interests or other dispositions that:

         (1)      are for fair market value on the date  thereof,  as determined
                  by the Board of Directors of BOK Financial  Corporation (which
                  determination shall be conclusive) and, after giving effect to
                  such disposition and to any possible  dilution,  BOK Financial
                  Corporation will own not less than 80% of the shares of Voting
                  Stock  of such  Principal  Subsidiary  Bank  then  issued  and
                  outstanding free and clear of any security interest;

         (2)      are made in compliance  with an order of a court or regulatory
                  authority of competent jurisdiction, as a condition imposed by
                  any such court or authority  permitting the acquisition by BOK
                  Financial  Corporation,  directly or indirectly,  of any other
                  bank or entity the activities of which are legally permissible
                  for a bank holding  company or a subsidiary  thereof to engage
                  in, or as an undertaking  made to such authority in connection
                  with such an acquisition;

         (3)      are made where such Principal Subsidiary Bank, having obtained
                  any necessary regulatory approvals, unconditionally guarantees
                  payment when due of the principal of and premium,  if any, and
                  interest on the Senior Debt Securities; or

                                                       

10


         (4)      are  made to BOK  Financial  Corporation  or any  Wholly-Owned
                  Subsidiary (as defined in the Indenture) if such  Wholly-Owned
                  Subsidiary  agrees  to be  bound  by  this  covenant  and  BOK
                  Financial  Corporation  agrees to maintain  such  Wholly-Owned
                  Subsidiary as a Wholly-Owned  Subsidiary.  Notwithstanding the
                  foregoing, any Principal Subsidiary Bank may be merged into or
                  consolidated with another banking institution  organized under
                  the  laws of the  United  States,  any  State  thereof  or the
                  District of Columbia if, after giving effect to such merger or
                  consolidation,  BOK Financial Corporation or any Wholly- Owned
                  Subsidiary owns at least 80% of the Voting Stock of such other
                  banking institution then issued and outstanding free and clear
                  of any  security  interest  and if,  immediately  after giving
                  effect  thereto  and  treating  any  such  resulting   banking
                  institution  thereafter as such Principal  Subsidiary Bank and
                  as a  Subsidiary  for purposes of the  Indenture,  no Event of
                  Default,  and no event  that,  after  the  giving of notice or
                  lapse of time or both,  would become an Event of Default,  has
                  occurred and is continuing.  A "Principal  Subsidiary Bank" is
                  defined in the Indenture to mean any Subsidiary (as defined in
                  the  Indenture)  that is a bank and has total  assets equal to
                  30%  or  more  of the  consolidated  assets  of BOK  Financial
                  Corporation  determined  as of the  date  of the  most  recent
                  audited financial statements of such entities. At present, the
                  only  Principal  Subsidiary  Bank  is the  Bank  of  Oklahoma,
                  National  Association.   "Voting  Stock"  is  defined  in  the
                  Indenture to mean stock of the class or classes having general
                  voting power under ordinary  circumstances to elect at least a
                  majority  of the board of  directors,  managers or trustees of
                  such  corporation  (irrespective of whether or not at the time
                  stock of any  other  class or  classes  will  have  contingent
                  voting rights).

         Consolidation, Merger and Sale of Assets

         The  Indenture   provides  that  BOK  Financial   Corporation  may  not
consolidate  with or merge into any other person or transfer its  properties and
assets substantially as an entirety to any person unless:

         (1)      the  person  formed by such  consolidation  or into  which BOK
                  Financial  Corporation  is merged  or the  person to which the
                  properties  and  assets of BOK  Financial  Corporation  are so
                  transferred is a corporation,  partnership or trust  organized
                  and validly existing under the laws of the United States,  any
                  State  thereof  or the  District  of  Columbia  and  expressly
                  assumes  by  a  supplemental  indenture  the  payment  of  the
                  principal of and  premium,  if any, and interest on the Senior
                  Debt  Securities,  as the case may be, and the  performance of
                  the other  covenants of BOK  Financial  Corporation  under the
                  applicable Indenture;

         (2)      immediately after giving effect to such transaction,  no Event
                  of Default or Default (as defined below),  as applicable,  and
                  no event that,  after  notice or lapse of time or both,  would
                  become an Event of  Default or  Default,  as  applicable,  has
                  occurred and is continuing; and

         (3)      certain other conditions are met.

         Defaults

         An "Event of  Default"  is defined in the  Indenture,  with  respect to
Senior Debt Securities of any series issued thereunder, as:

          (1)  default in the payment of principal of or premium, if any, on any
               Debt Security of that series at maturity;

          (2)  default  for 30 days  in the  payment  of  interest  on any  Debt
               Security of that series;

          (3)  default in the deposit of any sinking  fund  payment  when due in
               respect of that series;

                                                       

11


         (4)      default in the performance,  or breach,  of any other covenant
                  or warranty of BOK Financial  Corporation  in the Indenture or
                  in the Senior Debt Securities of that series, continued for 60
                  days after written notice to BOK Financial  Corporation by the
                  Trustee or to BOK Financial Corporation and the Trustee by the
                  holders of not less than 25% of the aggregate principal amount
                  of the outstanding Senior Debt Securities of that series;

         (5)      failure  to pay when  due any  indebtedness  of BOK  Financial
                  Corporation  or any  Principal  Subsidiary  Bank for  borrowed
                  money in excess of $5,000,000, or acceleration of the maturity
                  of  any  such   indebtedness  in  excess  of  such  amount  if
                  acceleration  results  from a  default  under  the  instrument
                  giving rise to such indebtedness and is not annulled within 60
                  days after due notice,  unless in either case such  default is
                  contested in good faith by appropriate proceedings;

         (6)      certain events of bankruptcy,  insolvency or reorganization of
                  BOK Financial  Corporation or any Principal  Subsidiary  Bank;
                  and

         (7)      any  other  Event of  Default  that may be  provided  for with
                  respect to Senior Debt Securities of that series.

         The  Indenture  provides  that, if any Event of Default with respect to
Senior Debt Securities of any series at the time outstanding  thereunder  occurs
and is  continuing,  either the  Trustee or the  holders of not less than 25% in
aggregate  principal  amount of the  outstanding  Senior Debt Securities of that
series may declare the  principal  amount of all Senior Debt  Securities of that
series to be due and payable  immediately  (provided that no such declaration is
required upon certain events of bankruptcy,  insolvency or reorganization),  but
upon certain  conditions  such  declaration  may be annulled  and past  defaults
(except,  unless  theretofore  cured,  a default in payment of  principal  of or
premium,  if any, or interest on the Senior Debt  Securities  of that series and
certain other specified  defaults) may be waived by the holders of a majority in
principal  amount of the  outstanding  Senior Debt  Securities of that series on
behalf of the holders of all Senior Debt Securities of that series. In the event
of the bankruptcy,  insolvency or reorganization  of BOK Financial  Corporation,
the  claims of  holders of the  Senior  Debt  Securities  would be subject as to
enforcement to the broad equity power of a United States  Bankruptcy  Court, and
to the determination by that court of the nature of the rights of such holders.

         The Indenture  contains a provision  entitling the Trustee,  subject to
the duty of the Trustee  upon the  occurrence  and  continuation  of an Event of
Default to act with the  required  standard of care,  to be  indemnified  by the
holders of any series of outstanding  Senior Debt Securities  thereunder  before
proceeding  to exercise any right or power under the Indenture at the request of
the holders of such series of Senior Debt  Securities.  The  Indenture  provides
that the  holders of a majority in  aggregate  principal  amount of  outstanding
Senior Debt Securities of any series  thereunder may direct the time, method and
place of conducting any proceeding for any remedy  available to the Trustee,  or
exercising  any trust or other power  conferred on the Trustee,  with respect to
the Senior Debt Securities of such series, provided that the Trustee may decline
to act if such  direction is contrary to law or the  Indenture or would  involve
the Trustee in personal liability.

                                                       
12


         BOK  Financial  Corporation  will  file  annually  with the  Trustee  a
certificate as to compliance with all conditions and covenants in the Indenture.

         Defeasance and Discharge

         The  Indenture  provides  that the terms of any  series of Senior  Debt
Securities  issued  thereunder  may provide that BOK Financial  Corporation  may
terminate  certain of its  obligations  under such Indenture with respect to the
Senior Debt Securities of such series on the terms and subject to the conditions
contained in such Indenture,  by (a) depositing  irrevocably with the applicable
Trustee as trust funds in trust:

         (1)      in the case of Senior Debt Securities denominated in a foreign
                  currency, money in such foreign currency or Foreign Government
                  Obligations  (as defined  below) of the foreign  government or
                  governments issuing such foreign currency,

         (2)      in the case of  Senior  Debt  Securities  denominated  in U.S.
                  dollars,  U.S.  dollars  or U.S.  Government  Obligations  (as
                  defined  below),  in each case in an amount  that  through the
                  payment of interest,  principal or premium, if any, in respect
                  thereof in accordance  with their terms will provide  (without
                  any reinvestment of such interest,  principal or premium), not
                  later  than  one  business  day  before  the  due  date of any
                  payment, money, or

         (3)      a  combination  of money and U.S.  Government  Obligations  or
                  Foreign Government Obligations,  as applicable,  sufficient to
                  pay the principal of or premium,  if any, and interest on, the
                  Senior Debt Securities of such series as such are due.

and  (b)  satisfying  certain  other  conditions   precedent  specified  in  the
applicable Indenture.  Such deposit and termination is conditioned,  among other
things,  upon  BOK  Financial  Corporation's  delivery  of  (a)  an  opinion  of
independent  counsel  that the  holders of the Senior  Debt  Securities  of such
series will have no federal income tax  consequences as a result of such deposit
and  termination  and (b) if the Senior Debt  Securities of such series are then
listed on an exchange,  an opinion of counsel that the Senior Debt Securities of
such series will not be  delisted  as a result of the  exercise of this  option.
Such termination will not relieve BOK Financial Corporation of its obligation to
pay when due the  principal  of, and interest on the Senior Debt  Securities  of
such series if the Senior Debt  Securities  of such series are not paid from the
money, Foreign Government Obligations or U.S.Government  Obligations held by the
applicable Trustee for payment thereof.

                                                       

13


         "U.S.  Government  Obligations"  means  securities  that are (1) direct
obligations  of the United  States of America  for the payment of which its full
faith  and  credit is  pledged  or (2)  obligations  of a person  controlled  or
supervised by and acting as an agency or instrumentality of the United States of
America the payment of which is  unconditionally  guaranteed as a full faith and
credit  obligation by the United States of America,  that, in either case, under
clauses (1) or (2) are not  callable or  redeemable  at the option of the issuer
thereof.  "Foreign  Government  Obligations"  means securities  denominated in a
foreign currency that are (1) direct obligations of a foreign government for the
payment of which its full faith and  credit is pledged or (2)  obligations  of a
person controlled or supervised by and acting as an agency or instrumentality of
a foreign  government  the payment of which is  unconditionally  guaranteed as a
full faith and credit  obligation  by such foreign  government,  that, in either
case,  under  clauses (1) or (2) are not callable or redeemable at the option of
the issuer thereof.

         The applicable  prospectus supplement will state whether any defeasance
provisions of the applicable  Indenture will apply to the Senior Debt Securities
offered thereby.

         Modification and Waiver

         Certain  modifications  and amendments of each of the Indentures may be
made by BOK  Financial  Corporation  and the  applicable  Trustee  only with the
consent of the holders of not less than a majority in aggregate principal amount
of the  outstanding  Senior Debt  Securities  of each series  issued  under such
Indenture and affected by the  modification or amendment,  provided that no such
modification  or  amendment  may,  without  the  consent  of the  holder of each
outstanding Debt Security issued under such Indenture and affected thereby:

         (1)      change  the Stated  Maturity  (as  defined  in the  applicable
                  indenture)  of  the  principal  of,  or  any   installment  of
                  principal of or interest on, any such Debt Security;

         (2)      reduce the principal amount of, or the premium, if any, or the
                  interest, if any, on, any such Debt Security;

         (3)      change the place of payment where,  or the coin or currency or
                  currency unit in which, any principal of, or premium,  if any,
                  or interest on, any such Debt Security is payable;

         (4)      impair the right to institute suit for the  enforcement of any
                  such payment on or after the Stated  Maturity  thereof (or, in
                  the case of redemption,  on or after the  Redemption  Date (as
                  defined in the applicable Indenture));

         (5)      reduce the above-stated  percentage of outstanding Senior Debt
                  Securities  of any series the  consent of the holders of which
                  is necessary to modify or amend the applicable Indenture; or

         (6)      modify the foregoing  requirements or reduce the percentage of
                  aggregate   principal   amount  of  outstanding   Senior  Debt
                  Securities  of any  series  required  to be  held  by  holders
                  seeking to waive  compliance  with certain  provisions  of the
                  applicable Indenture or seeking to waive certain defaults.

                                                       
14

         The holders of not less than a majority in aggregate  principal  amount
of the  outstanding  Senior Debt  Securities  of any series may on behalf of the
holders of all Senior  Debt  Securities  of that series  waive,  insofar as that
series is  concerned,  compliance  by BOK  Financial  Corporation  with  certain
restrictive provisions of the applicable Indenture. The holders of not less than
a  majority  in  aggregate  principal  amount  of the  outstanding  Senior  Debt
Securities  of any  series  may on  behalf of the  holders  of all  Senior  Debt
Securities of that series waive any past default under the applicable  Indenture
with  respect to that series,  except a default in the payment of the  principal
of, or premium,  if any, or interest on, any Debt  Security of that series or in
respect of a covenant or provision that under the applicable Indenture cannot be
modified or amended without the consent of the holder of each  outstanding  Debt
Security issued thereunder of the series affected.

         Certain  modifications  and amendments of each of the Indentures may be
made by BOK Financial Corporation and the applicable Trustee without the consent
of  holders  of  the  outstanding  Senior  Debt  Securities  issued  under  such
Indenture.

         Each Indenture provides that in determining  whether the holders of the
requisite  principal  amount of the outstanding  Senior Debt  Securities  issued
under such Indenture have given any request, demand,  authorization,  direction,
notice,  consent or waiver  thereunder or are present at a meeting of holders of
Senior Debt  Securities  for quorum  purposes,  the  principal  amount of a Debt
Security  denominated  in a foreign  currency or currency  unit will be the U.S.
dollar  equivalent,  determined  on the date of  original  issuance of such Debt
Security,  of the  principal  amount of such Debt Security or, in the case of an
Original Issue Discount Security, the U.S. dollar equivalent,  determined on the
date of original  issuance of such Debt  Security,  of the amount  determined as
provided above.

         Title

         BOK Financial Corporation,  the applicable Trustee and any agent of BOK
Financial  Corporation or the applicable  Trustee may treat the registered owner
of any Debt  Security as the absolute  owner  thereof  (whether or not such Debt
Security  is overdue and  notwithstanding  any notice to the  contrary)  for the
purpose of making payment and for all other  purposes.  See "GLOBAL  SECURITIES"
below.

         Replacement of Senior Debt Securities

         Any  mutilated   Debt  Security  will  be  replaced  by  BOK  Financial
Corporation at the expense of the holder upon surrender of such Debt Security to
the applicable  Trustee.  Senior Debt  Securities  that are  destroyed,  lost or
stolen  will be  replaced  by BOK  Financial  Corporation  at the expense of the
holder upon delivery to the applicable  Trustee of evidence of the  destruction,
loss  or  theft  thereof  satisfactory  to BOK  Financial  Corporation  and  the
applicable Trustee. In the case of a destroyed, lost or stolen Debt Security, an
indemnity  satisfactory to the applicable Trustee and BOK Financial  Corporation
may be  required  at the  expense of the holder of such Debt  Security  before a
replacement Debt Security will be issued.

                                                       
15

         Governing Law

         The Indentures and the Senior Debt  Securities will be governed by, and
construed in accordance with, the laws of the State of New York.

         Concerning the Trustees

         The Trustee will be named in the applicable prospectus supplement.

         Any Trustee may resign or be removed with respect to one or more series
of Senior Debt  Securities and a successor  Trustee may be appointed to act with
respect to such  series.  If two or more  persons  are  acting as  Trustee  with
respect to different series of Senior Debt Securities, each such Trustee will be
a Trustee of a trust under the  related  Indenture  separate  and apart from the
trust administered by any other such Trustee, and any action described herein to
be taken by the  "Trustee"  may then be taken by each such  Trustee with respect
to, and only with  respect to, the one or more series of Senior Debt  Securities
for which it is Trustee.

         In the ordinary course of business,  BOK Financial  Corporation and its
subsidiaries may conduct banking  transactions with a Trustee,  and such Trustee
and  its  affiliates  may  conduct  banking   transactions  with  BOK  Financial
Corporation and its subsidiaries.

         Ratings

         Particular series of Senior Debt Securities may be rated by one or more
nationally recognized statistical rating agencies. the rating agency or agencies
and rating or ratings to be  assigned  with  respect to a series of Senior  Debt
Securities  will be specified  in the  prospectus  supplement  for the series of
Senior Debt Securities.

                                GLOBAL SECURITIES

         Unless otherwise specified in the applicable prospectus supplement, the
Senior  Debt  Securities  will be  issued  in the  form  of one or  more  global
certificates (collectively,  with respect to each series or issue of Securities,
the "Global Security")  registered in the name of a depositary or a nominee of a
depositary.  Unless otherwise specified in the applicable prospectus supplement,
the  depositary  will be The  Depository  Trust Company  ("DTC").  BOK Financial
Corporation  has  been  informed  by DTC  that  its  nominee  will be Cede & Co.
("Cede").  Accordingly,  Cede is expected to be the initial registered holder of
all Senior  Debt  Securities  that are  issued in global  form.  No person  that
acquires a beneficial  interest in such Senior Debt  Securities will be entitled
to receive a certificate  representing such person's interest in the Senior Debt
Securities  except  as  set  forth  herein  or  in  the  applicable   prospectus
supplement.  Unless and until definitive Senior Debt Securities are issued under
the limited circumstances  described below, all references to actions by holders
of Senior Debt Securities  issued in global form shall refer to actions taken by
DTC  upon  instructions  from  its  Participants  (as  defined  below),  and all
references herein to payments and notices to holders shall refer to payments and
notices to DTC or Cede, as the registered holder of such Senior Debt Securities.

                                                       

16

         DTC is a company  organized  under the New York Banking Law, a "banking
organization"  within the  meaning  of the New York  Banking  Law,  that it is a
member of the  Federal  Reserve  System,  a  "clearing  corporation"  within the
meaning  of the  New  York  Uniform  Commercial  Code  and a  "clearing  agency"
registered  pursuant to Section 17A of the Exchange Act, and was created to hold
securities  for  its  participating   organizations   ("Participants")   and  to
facilitate  the  clearance  and  settlement  of  securities  transactions  among
Participants  through electronic  book-entry,  thereby  eliminating the need for
physical movement of certificates.  Participants  include securities brokers and
dealers,  banks,  trust  companies  and clearing  corporations,  and may include
certain other organizations. Indirect access to the DTC system also is available
to others such as banks, brokers, dealers and trust companies that clear through
or maintain a custodial  relationship  with a  Participant,  either  directly or
indirectly ("Indirect Participants").

         Persons that are not  Participants or Indirect  Participants but desire
to purchase,  sell or otherwise  transfer  ownership  of, or other  interests in
Senior  Debt  Securities  may  do so  only  through  Participants  and  Indirect
Participants.  Under a book-entry  format,  holders may experience some delay in
their  receipt of  payments,  as such  payments  will be  forwarded by the agent
designated  by BOK Financial  Corporation  to Cede, as nominee for DTC. DTC will
forward such payments to its Participants, which thereafter will forward them to
Indirect  Participants  or  holders.  Holders  will  not  be  recognized  by BOK
Financial Corporation or by the applicable registrar, transfer agent, Trustee or
Depositary, or their agents, as registered holders of the Senior Debt Securities
entitled to the benefits of the applicable Indenture. Beneficial owners that are
not  Participants  will be  permitted  to  exercise  their  rights  as such only
indirectly  through  and  subject to the  procedures  of  Participants  and,  if
applicable, Indirect Participants.

         Under the rules,  regulations and procedures creating and affecting DTC
and its operations as currently in effect (the "Rules"), DTC will be required to
make book-entry  transfers of Senior Debt Securities  among  Participants and to
receive  and  transmit  payments  to  Participants.  Participants  and  Indirect
Participants  with  which  beneficial  owners of  Senior  Debt  Securities  have
accounts  with respect to the Senior Debt  Securities  similarly are required by
the Rules to make book-entry transfers and receive and transmit such payments on
behalf of their respective account holders.

         Because  DTC can act only on  behalf of  Participants,  who in turn act
only on  behalf  of  Participants  or  Indirect  Participants,  and on behalf of
certain banks,  trust companies and other persons approved by it, the ability of
a  beneficial  owner of Senior Debt  Securities  issued in global form to pledge
such Senior Debt  Securities to persons or entities that do not  participate  in
the DTC system, or to otherwise act with respect to such Senior Debt Securities,
may be limited  due to the  unavailability  of  physical  certificates  for such
Senior Debt Securities.


                                                       
17


         DTC has advised BOK Financial Corporation that DTC will take any action
permitted to be taken by a registered holder of any Senior Debt Securities under
the applicable  Indenture only at the direction of one or more  Participants  to
whose accounts with DTC such Senior Debt Securities are credited.

         Unless otherwise specified in the applicable prospectus  supplement,  a
Global Security will be  exchangeable  for the relevant  definitive  Senior Debt
Securities registered in the names of persons other than DTC or its nominee only
if (1) DTC notifies BOK Financial  Corporation that it is unwilling or unable to
continue as depository for such Global  Security or if at any time DTC ceases to
be a clearing  agency  registered  under the  Exchange Act at a time when DTC is
required  to be so  registered  in  order  to act as  such  depository,  (2) BOK
Financial  Corporation   determines  that  such  Global  Security  shall  be  so
exchangeable  or (3) there has occurred and is continuing an Event of Default or
an event  that,  with the  giving  of notice  or lapse of time,  or both,  would
constitute an Event of Default with respect to such Senior Debt Securities.  Any
Global Security that is exchangeable  pursuant to the preceding sentence will be
exchangeable for Senior Debt Securities registered in such names as DTC directs.

         Upon the occurrence of any event described in the immediately preceding
paragraph,  DTC  is  generally  required  to  notify  all  Participants  of  the
availability through DTC of definitive Senior Debt Securities. Upon surrender by
DTC  of  the  Global  Security  representing  the  Securities  and  delivery  of
instructions  for  re-registration,  the registrar,  transfer agent,  Trustee or
Depositary,  as the case may be,  will  reissue the Senior  Debt  Securities  as
definitive  Senior Debt  Securities,  and thereafter such persons will recognize
the holders of such definitive  Senior Debt Securities as registered  holders of
Senior Debt Securities entitled to the benefits of the applicable Indenture.

         Except as described  above,  a Global  Security may not be  transferred
except  as a whole by DTC to a nominee  of DTC or by a nominee  of DTC to DTC or
another nominee of DTC or to a successor  depositary  appointed by BOK Financial
Corporation.  Except as described above, DTC may not sell,  assign,  transfer or
otherwise convey any beneficial  interest in a Global Security evidencing all or
part of any Senior  Debt  Securities  unless such  beneficial  interest is in an
amount equal to an authorized denomination for such Senior Debt Securities.

                                 USE OF PROCEEDS

         We will use the proceeds of the sale of the Senior Debt Securities for:

         **       acquisitions

         **       capital improvements

         **       repayment of short term bank borrowings

         **       start-up of new banking and bank related businesses

         **       expansion of existing business

         **       general working capital

                                                       
18


         We will tell you in the prospect supplement for what purpose we plan to
use the proceeds of any particular series of the Senior Debt Securities.

                              PLAN OF DISTRIBUTION

         We may sell the  offered  securities  (a) through  agents;  (b) through
underwriters or dealers; or (c) directly to one or more purchasers.

         By Agents

         Offered  securities  may be sold through  agents  designated by us. The
agents agree to use their  reasonable best efforts to solicit  purchases for the
period of their appointment.

         By Underwriters

         If  underwriters  are used in the sale, the offered  securities will be
acquired by the underwriters for their own account.  The underwriters may resell
the securities in one or more transactions,  including negotiated  transactions,
at a fixed public offering price or at varying prices  determined at the time of
sale. The  obligations of the  underwriters  to purchase the securities  will be
subject to certain  conditions.  The underwriters  will be obligated to purchase
all the securities of the series offered if any of the securities are purchased.
Any initial public  offering  price and any discounts or concessions  allowed or
re-allowed or paid to dealers may be changed from time to time.

         Direct Sales

         Offered  securities  may also be sold  directly by us. In this case, no
underwriters or agents would be involved.

         General Information

         Underwriters,  dealers and agents that  participate in the distribution
of the offered  securities may be  underwriters as defined in the Securities Act
of 1933 (the "Act"),  and any discounts or commissions  received by them from us
and any profit on the resale of the offered securities by them may be treated as
underwriting discounts and commissions under the Act. Any underwriters or agents
will be identified and their compensation described in a prospectus supplement.

         We may have  agreements  with the  underwriters,  dealers and agents to
indemnify them against certain civil  liabilities,  including  liabilities under
the Act,  or to  contribute  with  respect to payments  which the  underwriters,
dealers or agents may be required to make.

         Underwriters,  dealers and agents may engage in  transactions  with, or
perform  services for, us or our  subsidiaries  in the ordinary  course of their
businesses.


                                                       
19


                       RATIO OF EARNINGS TO FIXED CHARGES

                                     Six Months
                                        Ended          Year Ended December 31,
                                   June 30, 1998 1997   1996   1995  1994   1993
                                   ------------- ----   ----   ----  ----   ----
Ratio of Earnings to Fixed Charges:

Excluding Interest on Deposits           2.68     2.21   2.54   2.02  2.81  6.80
Including Interest on Deposits           1.55     1.43   1.43   1.40  1.57  1.73

         These   computations   include  BOK  Financial   Corporation   and  its
subsidiaries.  For these  ratios,  "earnings"  are  determined  by adding "fixed
charges"  income taxes to income from  continuing  operations.  "Fixed  charges"
consist of  interest  on all debt and  amortization  of  premiums  or  discounts
associated with debt.

                     VALIDITY OF THE SENIOR DEBT SECURITIES

         Unless otherwise indicated in the applicable prospectus supplement, the
validity of and Senior Debt  Securities  offered  hereby will be passed upon for
BOK Financial  Corporation by its counsel,  Frederic  Dorwart,  Esquire,  Tulsa,
Oklahoma.

                                     EXPERTS

         The  consolidated  financial  statements of BOK  Financial  Corporation
incorporated  by reference in BOK  Financial  Corporation's  Annual Report (Form
10-K) for the year ended  December  31, 1997 have been  audited by Ernst & Young
LLP,  independent  auditors,  as set  forth  in  their  report  incorporated  by
reference  therein  and  incorporated  herein by  reference.  Such  consolidated
financial  statements are incorporated herein by reference in reliance upon such
report  given  upon the  authority  of such firm as experts  in  accounting  and
auditing.

                                                       

20


                                     PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
                     --------------------------------------

Item 14. Other Expenses of Issuance and Distribution

         The  following  are  the  estimated  expenses  to be  incurred  by  BOK
Financial   Corporation  in  connection   with  the  Offer   described  in  this
Registration Statement:

         SEC registration fee.................................$ 73,750
         Printing and engraving expense.......................  20,000
         Fees and expenses of transfer agent...................  5,000
         Accounting fees and expenses...........................25,000
         Legal fees and expenses............................... 20,000
         Miscellaneous.......................................    5,000
              Total...........................................$148,750

Item 15. Indemnification of Directors and Officers

         The Oklahoma  Business  Corporation Act and Article VI of the Bylaws of
BOK Financial  Corporation  provide BOK Financial  Corporation with broad powers
and  authority  to  indemnify  its  directors  and  officers and to purchase and
maintain  insurance  for such  purposes.  Pursuant to such  statutory  and Bylaw
provisions,  BOK Financial  Corporation has purchased  insurance against certain
costs of indemnification of its officers and directors.

Item 16. Exhibits and Financial Statement Schedules.

         (a)      Exhibits.

Exhibit #     Description of Exhibits

1.0  Form of Underwriting Agreement

3.0  The Articles of Incorporation of BOK Financial Corporation, incorporated by
     reference to (i) Amended and Restated  Certificate of  Incorporation of BOK
     Financial Corporation filed with the Oklahoma Secretary of State on May 28,
     1991, filed as Exhibit 3.0 to S-1 Registration  Statement No. 33-90450, and
     (ii)  Amendment  attached  as  Exhibit  A  to  Information   Statement  and
     prospectus supplement filed November 20, 1991.

3.1  Bylaws of BOK Financial  Corporation,  incorporated by reference to Exhibit
     3.1 of S-1 Registration Statement No. 33-90450.

4.0  The rights of the holders of the Common  Stock and  Preferred  Stock of BOK
     Financial Corporation are set forth in its Certificate of Incorporation.

4.1  Form of Senior Debt Indenture.

                                                       
21


5.0  Opinion of  Frederic  Dorwart,  Lawyers  regarding  validity of Senior Debt
     Securities.

23.0 Consent of independent auditors - Ernst & Young LLP.

27.0 Financial  Data  Schedule  for ended  December 31,  1997,  incorporated  by
     reference to Exhibit  27.0 of Form 10-K for the fiscal year ended  December
     31, 1997

27.1 Restated Financial Data Schedule, incorporated by reference to Exhibit 27.1
     of Form 10-Q for the fiscal quarter ended June 30, 1998

99.0 Additional Exhibits.

99.1 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-44121 for Bank of Oklahoma Master Thrift Plan and Trust, incorporated by
     reference to Exhibit  99.1 of Form 10-K for the fiscal year ended  December
     31, 1993.

99.2 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-44122 for BOK  Financial  Corporation  1991  Special  Stock Option Plan,
     incorporated  by reference to Exhibit 99.2 of Form 10-K for the fiscal year
     ended December 31, 1993.

99.3 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-55312 for BOK Financial Corporation 1992 Stock Option Plan, incorporated
     by  reference  to  Exhibit  99.3 of Form  10-K for the  fiscal  year  ended
     December 31, 1993.

99.4 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-70102 for BOK Financial Corporation 1993 Stock Option Plan, incorporated
     by  reference  to  Exhibit  99.4 of Form  10-K for the  fiscal  year  ended
     December 31, 1993.

99.5 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-79834 for BOK Financial Corporation 1994 Stock Option Plan, incorporated
     by  reference  to  Exhibit  99.5 of Form  10-K for the  fiscal  year  ended
     December 31, 1994.

99.6 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-79836 for BOK Financial Corporation  Directors' Stock Compensation Plan,
     incorporated  by reference to Exhibit 99.6 of Form 10-K for the fiscal year
     ended December 31, 1994.

99.7 Undertakings  incorporated by reference into S-8 Registration Statement No.
     33-32642 for BOK Financial Corporation 1997 Stock Option Plan, Incorporated
     by  reference  to  Exhibit  99.7 of Form  10-K for the  fiscal  year  ended
     December 31, 1997.

                                                       
22



(b)  Financial Statement Schedules.

     All schedules either are not applicable or the information required thereby
     is included in the financial statements or notes thereto.

Item 17. Undertakings.

(a)      The undersigned registrant hereby undertakes:

         (1)      To file,  during any period in which offers or sales are being
                  made,  a   post-effective   amendment  to  this   registration
                  statement:

                    (i)  To include any prospectus  required by Section 10(a)(3)
                         of the Securities Act of 1933;

                    (ii) To  reflect  in the  prospectus  any  facts  or  events
                         arising  after the effective  date of the  registration
                         statement (or the most recent post-effective  amendment
                         thereof)  which,  individually  or  in  the  aggregate,
                         represent a fundamental  change in the  information set
                         forth in the  registration  statement.  Notwithstanding
                         the  foregoing,  any increase or decrease in the volume
                         of  securities  offered (if the total  dollar  value of
                         securities  offered  would not  exceed  that  which was
                         registered)  and any deviation from the low or high and
                         of  the  estimated   maximum   offering  range  may  be
                         reflected  in the  form of  prospectus  filed  with the
                         Commission   pursuant   to  Rule   424(b)  if,  in  the
                         aggregate, the changes in volume and price represent no
                         more than 20% change in the maximum aggregate  offering
                         price set  forth in the  "Calculation  of  Registration
                         Fee" table in the effective registration statement.

                    (iii)To include any  material  information  with  respect to
                         the plan of  distribution  not previously  disclosed in
                         the  registration  statement or any material  change to
                         such   information  in  the   registration   statement;
                         provided,   however,   that  paragraphs  (a)(1)(i)  and
                         (a)(1)(ii) do not apply if the information  required to
                         be  included  in a  post-effective  amendment  by those
                         paragraphs is contained in periodic  reports filed with
                         or  furnished  to  the  Commission  by  the  registrant
                         pursuant  to  Section  13  or  Section   15(d)  of  the
                         Securities  Exchange Act of 1934 that are  incorporated
                         by reference in the registration statement.

         (2)      That, for the purpose of determining  any liability  under the
                  Securities  Act of 1933,  each such  post-effective  amendment
                  shall be deemed to be a new registration statement relating to
                  the  securities  offered  therein,  and the  offering  of such
                  securities at that time shall be deemed to be the initial bona
                  fide offering thereof.

                                                       

23


         (3)      To  remove  from  registration  by means  of a  post-effective
                  amendment any of the securities  being registered which remain
                  unsold at the termination of the offering.

(b)      The  undersigned  registrant  hereby  undertakes  that, for purposes of
         determining any liability under the Securities Act of 1933, each filing
         of the registrant's  annual report pursuant to Section 13(a) or Section
         15(d) of the Securities  Exchange Act of 1934 that is  incorporated  by
         reference  in the  registration  statement  shall be deemed to be a new
         registration  statement relating to the securities offered therein, and
         the offering of such  securities at that time shall be deemed to be the
         initial bona fide offering thereof.

(c)       Insofar as  indemnification  for  liabilities  arising  under the
          Securities  Act of 1933 may be  permitted to  directors,  officers and
          controlling  persons  of the  registrant  pursuant  to  the  foregoing
          provisions,  or otherwise, the registrant has been advised that in the
          opinion of the  Commission  such  indemnification  is  against  public
          policy as expressed in the Act and is,  therefore,  unenforceable.  In
          the event that a claim for  indemnification  against such  liabilities
          (other than the payment by the registrant of expenses incurred or paid
          by a director,  officer or controlling person of the registrant in the
          successful  defense of any action,  suit or proceeding) is asserted by
          such director,  officer or controlling  person in connection  with the
          securities  being  registered,  the  registrant  will,  unless  in the
          opinion of its  counsel  the matter  has been  settled by  controlling
          precedent,  submit to a court of appropriate jurisdiction the question
          of whether  such  indemnification  by it is against  public  policy as
          expressed in the Act and will be governed by the final adjudication of
          such issue.

(d)      The undersigned registrant hereby undertakes to file an application for
         the purpose of determining the eligibility of the trustee in respect of
         the Indenture and the  Subordinated  Indenture to act under  subsection
         (a) of Section 310 of the Trust  Indenture Act in  accordance  with the
         rules  and  regulations  prescribed  by the  Commission  under  Section
         305(b)(2) of the Act.

                                   SIGNATURES

         Pursuant  to the  requirements  of the  Securities  Act  of  1933,  the
Registrant has duly caused this Registration Statement or Amendment to be signed
on its behalf by the  undersigned,  thereunto  duly  authorized,  in the City of
Tulsa, State of Oklahoma, on October 12, 1998.

                                           BOK FINANCIAL CORPORATION

                                      By   /s/ George B. Kaiser
                                          ____________________________________
                                           GEORGE B. KAISER,
                                           Chairman of the Board of Directors

                                                       
24

    Pursuant to the requirements of the Securities Act of 1933, as amended,
this  Amendment  to the  Registration  Statement  has been  signed  below by the
following persons in the capacities and on the date indicated.


Signature                              Title                      Date


 /s/ George B. Kaiser        Chairman of the Board          October 13, 1998
George B. Kaiser             of BOK Financial Corporation


/s/ Stanley A. Lybarger      President, Chief Executive     October 13, 1998
Stanley A. Lybarger          Officer, and Director of
                             BOK Financial Corporation


 /s/ James A. White          Executive Vice President,      October 13, 1998
James A. White               Chief Financial Officer,
                             and Treasurer of BOK
                              Financial Corporation


 /s/ John C. Morrow          Controller of BOK              October 13, 1998
John C. Morrow               Financial Corporation


 /s/ W. Wayne Allen          Director of BOK Financial      October 13, 1998
W. Wayne Allen               Corporation


 /s/ James E. Barnes         Director of BOK Financial      October 13, 1998
James E. Barnes              Corporation


 /s/ Sharon J. Bell          Director of BOK Financial      October 13, 1998
Sharon J. Bell               Corporation


 /s/ Glenn A. Cox            Director of BOK Financial      October 13, 1998
Glenn A. Cox                 Corporation


25


 /s/ Robert H. Donaldson     Director of BOK Financial      October 13, 1998
Robert H. Donaldson          Corporation


 /s/ William E. Durrett      Director of BOK Financial      October 13, 1998
William E. Durrett           Corporation


 /s/ James O. Goodwin        Director of BOK Financial      October 13, 1998
James O. Goodwin             Corporation


 /s/ V. Burns Hargis         Director of BOK Financial      October 13, 1998
V. Burns Hargis              Corporation


 /s/ Howard E. Janzen        Director of BOK Financial      October 13, 1998
Howard E. Janzen             Corporation


 /s/ E. Carey Joullian IV    Director of BOK Financial      October 13, 1998
E. Carey Joullian IV                 Corporation


 /s/ Robert J. LaFortune     Director of BOK Financial      October 13, 1998
Robert J. LaFortune          Corporation


 /s/ Philip C. Lauinger      Director of BOK Financial      October 13, 1998
Philip C. Lauinger           Corporation


 /s/ David R. Lopez          Director of BOK Financial      October 13, 1998
David R. Lopez               Corporation


 /s/ John Massey             Director of BOK Financial      October 13, 1998
John Massey                  Corporation


                             Director of BOK Financial      October 13, 1998
- -----------------------------Corporation
Frank A. McPherson           


 /s/ Steve E. Moore          Director of BOK Financial      October 13, 1998
Steve E. Moore               Corporation
               

26


 /s/ J. Larry Nichols        Director of BOK Financial       October 13, 1998
J. Larry Nichols             Corporation


                            Director of BOK Financial        October 13, 1998
- ----------------------------Corporation
Robert L. Parker, Sr.        


 /s/ James W. Pielsticker    Director of BOK Financial      October 13, 1998
James W. Pielsticker         Corporation


 /s/ E.C. Richards           Director of BOK Financial      October 13, 1998
E.C. Richards                Corporation


 /s/ James A. Robinson       Director of BOK Financial      October 13, 1998
James A. Robinson            Corporation


                             Director of BOK Financial      October 13, 1998
- ----------------------------Corporation
L. Francis Rooney            


 /s/ David J. Tipeconnic     Director of BOK Financial      October 13, 1998
David J. Tippeconnic         Corporation


                             Director of BOK Financial      October 13, 1998
- ----------------------------Corporation
Tom E. Turner                


                             Director of BOK Financial      October 13, 1998
- ---------------------------  Corporation
Robert L. Zemanek            


27

                                POWER OF ATTORNEY

         Each person whose signature  appears below hereby  authorizes George B.
Kaiser and James A.  White,  or either of them,  to file one or more  amendments
(including   post-effective   amendments)  to  Registration   Statement   number
______________,  which  amendments  may make such  changes  in the  Registration
Statement  as Mr.  Kaiser or Mr. White deems  appropriate,  and each such person
hereby  appoints  George B.  Kaiser and James A.  White,  or either of them,  as
attorney-in-fact   to  execute  in  the  name  and  on  behalf  of  each  person
individually,  and in each  capacity  stated  below,  any such  amendment to the
Registration Statement.


Signature                                Title                      Date

 /s/ George B. Kaiser        Chairman of the Board           October 13, 1998
George B. Kaiser             of BOK Financial Corporation


/s/ Stanley A. Lybarger      President, Chief Executive     October 13, 1998
Stanley A. Lybarger          Officer, and Director of
                             BOK Financial Corporation


 /s/ James A. White          Executive Vice President,      October 13, 1998
James A. White               Chief Financial Officer,
                             and Treasurer of BOK
                             Financial Corporation


 /s/ John C. Morrow          Controller of BOK              October 13, 1998
John C. Morrow               Financial Corporation


 /s/ W. Wayne Allen          Director of BOK Financial      October 13, 1998
W. Wayne Allen               Corporation


 /s/ James E. Barnes         Director of BOK Financial      October 13, 1998
James E. Barnes              Corporation


 /s/ Sharon J. Bell          Director of BOK Financial      October 13, 1998
Sharon J. Bell               Corporation

28

 /s/ Glenn A. Cox            Director of BOK Financial      October 13, 1998
Glenn A. Cox                 Corporation


 /s/ Robert H. Donaldson     Director of BOK Financial      October 13, 1998
Robert H. Donaldson          Corporation


 /s/ William E. Durrett      Director of BOK Financial      October 13, 1998
William E. Durrett           Corporation


 /s/ James O. Goodwin        Director of BOK Financial      October 13, 1998
James O. Goodwin             Corporation


 /s/ V. Burns Hargis         Director of BOK Financial      October 13, 1998
V. Burns Hargis              Corporation


 /s/ Howard E. Janzen        Director of BOK Financial      October 13, 1998
Howard E. Janzen             Corporation


 /s/ E. Carey Joullian IV    Director of BOK Financial      October 13, 1998
E. Carey Joullian IV         Corporation


 /s/ Robert J. LaFortune     Director of BOK Financial      October 13, 1998
Robert J. LaFortune          Corporation


 /s/ Philip C. Lauinger      Director of BOK Financial      October 13, 1998
Philip C. Lauinger           Corporation


 /s/ David R. Lopez          Director of BOK Financial      October 13, 1998
David R. Lopez               Corporation


 /s/ John Massey             Director of BOK Financial      October 13, 1998
John Massey                  Corporation


                             Director of BOK Financial      October 13, 1998
- ---------------------------- Corporation
Frank A. McPherson                   

29

 /s/ Steve E. Moore          Director of BOK Financial      October 13, 1998
Steve E. Moore               Corporation


 /s/ J. Larry Nichols        Director of BOK Financial      October 13, 1998
J. Larry Nichols             Corporation


                             Director of BOK Financial      October 13, 1998
- ---------------------------- Corporation
Robert L. Parker, Sr.        


 /s/ James W. Pielsticker    Director of BOK Financial      October 13, 1998
 James W. Pielsticker        Corporation
                 


 /s/ E.C. Richards           Director of BOK Financial      October 13, 1998
E.C. Richards                Corporation


 /s/ James A. Robinson       Director of BOK Financial      October 13, 1998
James A. Robinson            Corporation


                             Director of BOK Financial      October 13, 1998
- ---------------------------- Corporation
L. Francis Rooney            


 /s/ David J. Tipeconnic     Director of BOK Financial      October 13, 1998
David J. Tippeconnic         Corporation


                             Director of BOK Financial      October 13, 1998
- ---------------------------- Corporation
Tom E. Turner                


                             Director of BOK Financial      October 13, 1998
- ---------------------------- Corporation
Robert L. Zemanek            


                                 

                                INDEX TO EXHIBITS


Exhibit                                                      
Number   Description of Exhibits                                

1.0      Form of Underwriting Agreement

4.1      Form of Senior Debt Indenture

5.0      Opinion of Frederic Dorwart, Lawyers

23.0     Consent of Independent Auditors - Ernst & Young LLP