EXHIBIT 4.3



                   AGREEMENT AS TO EXPENSES AND LIABILITIES

     AGREEMENT AS TO EXPENSES AND LIABILITIES (this "Agreement") dated as of
June 4, 1997, between SOUTHWEST BANCORP, INC. an Oklahoma corporation (the
"Company"), and SBI CAPITAL TRUST, a Delaware business trust (the "Trust").

                                   RECITALS

     WHEREAS, the Trust intends to issue its common securities (the "Common
Securities") to, and receive Debentures from, the Company and to issue and sell
one million five hundred (1,000,500) of its 9.30% Cumulative Trust Preferred
Securities (the "Preferred Securities") with such powers, preferences and
special rights and restrictions as are set forth in the Amended and Restated
Trust Agreement of the Trust dated as of June 4, 1997, as the same may be
amended from time to time (the "Trust Agreement");

     WHEREAS, the Company shall directly or indirectly own all of the Common
Securities of the Trust and shall issue the Debentures;

     NOW, THEREFORE, in consideration of the purchase by each holder of the
Preferred Securities, which purchase the Company hereby agrees shall benefit the
Company and which purchase the Company acknowledges shall be made in reliance
upon the execution and delivery of this Agreement, the Company, including in its
capacity as holder of the Common Securities, and the Trust hereby agree as
follows:

                                   ARTICLE I

     SECTION 1.1.     GUARANTEE BY THE COMPANY.

     Subject to the terms and conditions hereof, the Company, including in its
capacity as holder of the Common Securities, hereby irrevocably and
unconditionally guarantees to each person or entity to whom the Trust is now or
hereafter becomes indebted or liable (the "Beneficiaries") the full payment when
and as due, of any and all Obligations (as hereinafter defined) to such
Beneficiaries. As used herein, "Obligations" means any costs, expenses or
liabilities of the Trust other than obligations of the Trust to pay to holders
of any Preferred Securities or other similar interests in the Trust the amounts
due such holders pursuant to the terms of the Preferred Securities or such other
similar interests, as the case may be. This Agreement is intended to be for the
benefit of, and to be enforceable by, all such Beneficiaries, whether or not
such Beneficiaries have received notice hereof.

     SECTION 1.2.     TERM OF AGREEMENT.

     This Agreement shall terminate and be of no further force and effect upon
the later of (a) the date on which full payment has been made of all amounts
payable to all holders of all the Preferred Securities (whether upon redemption,
liquidation, exchange or otherwise); and (b) the date on which there are no
Beneficiaries remaining; provided, however, that this Agreement shall continue
to be effective or shall be reinstated, as the case may be, if at any time any
holder of Preferred Securities or any Beneficiary must restore payment of any
sums paid under the Preferred Securities, under any obligation, under the
Preferred Securities Guarantee Agreement dated the date hereof by the Company
and State Street Bank and Trust Company as guarantee trustee, or under this
Agreement for any reason whatsoever. This Agreement is continuing, irrevocable,
unconditional and absolute.

     SECTION 1.3.     WAIVER OF NOTICE.

     The Company hereby waives notice of acceptance of this Agreement and of any
obligation to which it applies or may apply, and the Company hereby waives
presentment, demand for payment, protest, notice of nonpayment, notice of
dishonor, notice of redemption and all other notices and demands.

 
     SECTION 1.4.     NO IMPAIRMENT.

     The obligations, covenants, agreements and duties of the Company under this
Agreement shall in no way be affected or impaired by reason of the happening
from time to time of any of the following:

        (a) the extension of time for the payment by the Trust of all or any
portion of the obligations or for the performance of any other obligation under,
arising out of, or in connection with, the obligations;

        (b) any failure, omission, delay or lack of diligence on the part of the
Beneficiaries to enforce, assert or exercise any right, privilege, power or
remedy conferred on the Beneficiaries with respect to the obligations or any
action on the part of the Trust granting indulgence or extension of any kind; or

        (c) the voluntary or involuntary liquidation, dissolution, sale of any
collateral, receivership, insolvency, bankruptcy, assignment for the benefit of
creditors, reorganization, arrangement composition or readjustment of debt of,
or other similar proceedings affecting, the Trust or any of the assets of the
Trust.

     There shall be no obligation of the Beneficiaries to give notice to, or
obtain the consent of, the Company with respect to the happening of any of the
foregoing.

     SECTION 1.5.     ENFORCEMENT.

     A Beneficiary may enforce this Agreement directly against the Company, and
the Company waives any right or remedy to require that any action be brought
against the Trust or any other person or entity before proceeding against the
Company.

                                  ARTICLE II

     SECTION 2.1.     BINDING EFFECT.

     All guarantees and agreements contained in this Agreement shall bind the
successors, assigns, receivers, trustees and representatives of the Company and
shall inure to the benefit of the Beneficiaries.

     SECTION 2.2.     AMENDMENT.

     So long as there remains any Beneficiary or any Preferred Securities of any
series are outstanding, this Agreement shall not be modified or amended in any
manner adverse to such Beneficiary or to the holders of the Preferred
Securities.

     SECTION 2.3.     NOTICES.

     Any notice, request or other communication required or permitted to be
given hereunder shall be given in writing by delivering the same by facsimile
transmission (confirmed by mail), telex, or by registered or certified mail,
addressed as follows (and if so given, shall be deemed given when mailed or upon
receipt of an answer back, if sent by telex):

     SBI Capital Trust, 608 South Main Street, Stillwater, Oklahoma,  74074.
     Facsimile No.: 405-742-4799 Attention: Kerby E. Crowell

     Southwest Bancorp, Inc., 608 South Main Street, Stillwater, Oklahoma
     74074. Facsimile No.: 405-742-4799 Attention: Kerby E. Crowell

 
     SECTION 2.4     This agreement shall be governed by and construed and
interpreted in accordance with the laws of the State of Oklahoma (without regard
to conflict of laws principles).

     THIS AGREEMENT is executed as of the day and year first above written.

                              SOUTHWEST BANCORP, INC.



                         By:  /s/ Robert L. McCormick, Jr.
                              ------------------------------------------------
                              Robert L. McCormick, Jr., President

 
                              SBI CAPITAL TRUST




                         By:  /s/ Robert L. McCormick, Jr.
                              ------------------------------------------------
                              Robert L. McCormick, Jr., Administrative Trustee