EXHIBIT 10.1

                       MID-PENINSULA SHAREHOLDER AGREEMENT

     This Shareholder Agreement ("Agreement") is made and entered into on 
June 26, 1996, by and between Cupertino National Bancorp ("Cupertino") and 
each of the other persons executing this Agreement (each such person is 
referred to individually as a "Mid-Peninsula Shareholder" and collectively 
referred to as the "Mid-Peninsula Shareholders"), with reference to the 
following facts:

     A.   Mid-Peninsula Bancorp ("Mid-Peninsula") and Cupertino have entered 
into that certain Agreement and Plan of Reorganization and Merger 
("Reorganization Agreement"), dated as of June 5, 1996, pursuant to which 
Cupertino will merge with and into Mid-Peninsula (the "Merger"), 
Mid-Peninsula will change its name to Greater Bay Bancorp ("Bancorp") and 
Mid-Peninsula will pay consideration to Cupertino Shareholders in the form of 
Bancorp common stock.

     B.   Each of the Mid-Peninsula Shareholders is also a director or 
executive officer of Mid-Peninsula.

     C.   In order to induce Cupertino to enter into the Reorganization 
Agreement, the Mid-Peninsula Shareholders desire to enter into this Agreement 
solely in their capacity as Mid-Peninsula Shareholders.

     NOW, THEREFORE, in consideration of the promises and of the respective 
representations, warranties and covenants, agreements and conditions 
contained herein and in the Reorganization Agreement, the parties hereto 
agree as follows:

1.   AGREEMENTS OF MID-PENINSULA SHAREHOLDERS.

     1.1  AGREEMENT TO VOTE.  At any meeting of shareholders of Mid-Peninsula 
or in connection with any solicitation of the written consent of 
Mid-Peninsula Shareholders to approve the Reorganization Agreement and the 
transactions contemplated thereby, each of the Mid-Peninsula Shareholders 
shall vote or cause to be voted all shares of Mid-Peninsula common stock 
("Mid-Peninsula Share" or "Mid-Peninsula Shares") owned by each such 
Mid-Peninsula Shareholder, and any other Mid-Peninsula Shares hereafter 
acquired by each such Mid-Peninsula Shareholder, in favor of, and to approve, 
the principal terms of the Merger and any other matter contemplated by the 
Reorganization Agreement which requires the approval of the Mid-Peninsula 
Shareholders.

     1.2  AGREEMENT TO RECOMMEND.  Unless the Board of Directors of 
Mid-Peninsula shall have determined that they have a fiduciary duty to the 
Mid-Peninsula Shareholders to recommend that the Mid-Peninsula Shareholders 
not vote in favor of approval of the transactions contemplated by the 
Reorganization Agreement, each Mid-Peninsula Shareholder shall recommend to 
the Mid-Peninsula Shareholders to vote in favor of, and to approve, the 
principal

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terms of the Merger and any other matter contemplated by the 
Reorganization Agreement.

     1.3  RESTRICTIONS ON DISPOSITIONS.  Each Mid-Peninsula Shareholder 
agrees that he will not pledge or otherwise encumber, nor sell, assign or 
otherwise dispose of, any Mid-Peninsula Shares currently owned or acquired by 
such Mid-Peninsula Shareholder after the date of this Agreement, except (i) 
with the prior written consent of Cupertino (which shall not be unreasonably 
withheld); (ii) pursuant to the Reorganization Agreement; or (iii) by a bona 
fide pledge to secure a loan made on a full-recourse basis.

     1.4  NEGOTIATIONS WITH OTHER PARTIES.  Each Mid-Peninsula Shareholder 
agrees that he will not, directly or indirectly, solicit or encourage any 
inquiries, discussions or proposals from, or enter into, or continue any 
discussions, negotiations or agreements relating to, or vote in favor of any 
proposal or transactions for disposition of all or part of the business or 
assets of Mid-Peninsula or any subsidiary thereof, or the acquisition of all 
or part of Mid-Peninsula's or any subsidiary of Mid-Peninsula's voting 
securities or any business combination with any person other than Cupertino 
or any wholly-owned subsidiary of Cupertino unless, upon advice of counsel, 
the Board of Directors of Mid-Peninsula shall have determined that any duty 
to refrain from any act pursuant to this Section 1.4 is inconsistent with the 
continuing fiduciary duty of the Board of Directors to the Mid-Peninsula 
Shareholders.

2.   REPRESENTATIONS AND WARRANTIES OF MID-PENINSULA SHAREHOLDERS.

     Each of the Mid-Peninsula Shareholders severally and not jointly, 
represents and warrants to and agrees with Cupertino, solely with respect to 
himself or herself, as follows:

     2.1  CAPACITY.  Each such Mid-Peninsula Shareholder has all the 
requisite capacity and authority to enter into and perform such Mid-Peninsula 
Shareholder's obligations under this Agreement.

     2.2  BINDING AGREEMENT.  This Agreement constitutes the valid and 
legally binding obligation of each such Mid-Peninsula Shareholder.

     2.3  NON-CONTRAVENTION.  The execution and delivery of this Agreement by 
each such Mid-Peninsula Shareholder does not, and the performance by such 
Mid-Peninsula Shareholder's obligations hereunder and the consummation by 
such Mid-Peninsula Shareholder of the transactions contemplated hereby will 
not, violate or conflict with or constitute a default under any agreement, 
instrument, contract or other obligation or any order,

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arbitration award, judgment or decree to which such Mid-Peninsula Shareholder 
is a party or by which such Mid-Peninsula Shareholder is bound, or any 
statute, rule or regulation to which such Mid-Peninsula Shareholder or any of 
such Mid-Peninsula Shareholder's property is subject.

     2.4  OWNERSHIP OF SHARES.  Schedule 1 hereto correctly sets forth the 
number of Mid-Peninsula Shares owned by each Mid-Peninsula Shareholder, or 
with respect to which each Mid-Peninsula Shareholder has good title to all of 
the Mid-Peninsula Shares indicated as owned by such Mid-Peninsula Shareholder 
in the capacity set forth on Schedule 1 as of the date indicated on such 
Schedule 1, and such Mid-Peninsula Shares are so owned free and clear of any 
liens, security interest, charges or other encumbrances, except as set forth 
in such Schedule 1.

3.   TERMINATION.

     3.1  TERMINATION DATE.  This Agreement shall terminate and be of no 
further force and effect immediately upon the earlier of:  (a) consummation 
of the Merger; or (b) termination of the Reorganization Agreement in 
accordance with the terms thereof.

     3.2  EFFECT OF TERMINATION.  Upon the termination of this Agreement in 
accordance with Section 3.1 hereof, the respective obligations of the parties 
hereto shall immediately become void and have no further force or effect.

4.   SPECIFIC PERFORMANCE.  The parties hereto recognize and agree that 
monetary damages will not compensate adequately the parties hereto for 
nonperformance. Accordingly, each party agrees that his obligations shall be 
enforceable by court order requiring specific performance.

5.   MISCELLANEOUS.

     5.1  EXPENSES.  Each party hereto shall pay its own costs and expenses, 
including, but not limited to, those of its attorneys and accountants, in 
connection with this Agreement and transactions covered and contemplated 
hereby.

     5.2  NOTICES.  All notices, demands or other communications hereunder 
shall be in writing and shall be deemed to have been duly given if delivered 
in person, by telex, telecopy, facsimile transmission, or by United States 
mail, certified or registered, with return receipt requested, or otherwise 
actually delivered as follows:

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          (a)  If to Mid-Peninsula Bancorporation:

               Mid-Peninsula Bancorp
               420 Cowper Street
               Palo Alto, CA  94301-1504
               Attention:  David L. Kalkbrenner, President
               Telephone: (408) 323-5150
               Telecopier: (408) 323-7421
               
          With copies to:

               Bronson, Bronson & McKinnon
               10 Almaden Blvd., Suite 600
               San Jose, CA  95113-2237
               Attention:  Glenn T. Dodd
               Telephone: (408) 293-0599
               Telecopier: (408) 999-6553
               Attention:  John W. Carr
               Telephone: (415) 986-4200
               Telecopier: (415) 982-1394

          (b)  If to a Cupertino Shareholder:

               Cupertino National Bancorp
               20230 Stevens Creek Boulevard
               Cupertino, CA 95014
               Attention:  C. Donald Allen, President
               Telephone: (408) 996-1144
               Telecopier:  (408) 996-0657

          With copies to:

               Manatt, Phelps & Phillips
               11355 W. Olympic Boulevard
               Los Angeles, CA 90064
               Attention:  Paul H. Irving
                           William T. Quicksilver
               Telephone: (310) 312-4000
               Telecopier: (310) 312-4224    

The persons or address to which mailings or deliveries shall be made may 
change from time to time by notice given pursuant to the provisions of this 
Section 5.2.  Any notice, demand or other communication given pursuant to the 
provisions of this Section 5.2 shall be deemed to have been given on the date 
delivered or three days following the date mailed, as the case may be.

     5.3  SUCCESSORS AND ASSIGNS.  All terms and provisions of this Agreement 
shall be binding upon and inure to the benefit of the parties hereto and 
their respective transferees, successors and assigns; provided, however, 
that, except as otherwise contemplated herein, this Agreement and all rights, 
privileges, duties and obligations of the parties hereto may not be assigned 
or delegated by any party hereto without the prior written

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consent of the other parties to this Agreement and any purported assignment 
in violation of this Section 5.3 shall be null and void.

     5.4  THIRD PARTY BENEFICIARIES.  Each party hereto intends that this 
Agreement shall not benefit, or create any right or cause of action in or on 
behalf of, any person other than the parties hereto.  As used in this 
Agreement, the term party or parties shall refer only to Cupertino and the 
Mid-Peninsula Shareholders, or any of them.

     5.5  COUNTERPARTS.  This Agreement may be executed in one or more 
counterparts, all of which taken together shall constitute one instrument.

     5.6  GOVERNING LAW.  This Agreement is made and entered into in the 
State of California and the laws of that state shall govern the validity and 
interpretation hereof and the performance of the parties hereto of their 
respective duties and obligations hereunder.

     5.7  CAPTIONS.  The captions contained in this Agreement are for
convenience of reference only and do not form a part of this Agreement.

     5.8  WAIVER AND MODIFICATION.  No waiver of any term, provision or 
condition of this Agreement, whether by conduct or otherwise, in any one or 
more instances, shall be deemed to be or construed as a further or continuing 
waiver of any such term, provision or condition of this Agreement.  This 
Agreement may be modified or amended only by an instrument of equal formality 
signed by the parties or their duly authorized agents.

     5.9  ATTORNEYS' FEES.  In the event any of the parties to this Agreement 
brings an action or suit against any other party by reason of any breach of 
any covenant, agreement, representation, warranty or other provision hereof, 
or any breach of any duty or obligation created hereunder by such other 
party, the prevailing party in whose favor final judgment is entered shall be 
entitled to have and recover of and from the losing party all reasonable 
costs and expenses incurred or sustained by such prevailing party in 
connection with such suit or action, including without limitation, legal fees 
and court costs (whether or not taxable as such).

     5.10 ENTIRE AGREEMENT.  The making, execution and delivery of this 
Agreement by the parties hereto have been encouraged by no representations, 
statements, warranties or agreements other than those herein expressed.  This 
Agreement embodies the entire understanding of the parties and there are no 
further or other agreements or understandings, written or oral, in effect 
between the parties relating to the subject matter hereof, unless expressly 
referred to by reference herein.

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     5.11 SEVERABILITY.  Whenever possible, each provision of this Agreement 
and every related document shall be interpreted in such manner as to be valid 
under applicable law.  However, if any provision of any of the foregoing 
shall be invalid or prohibited under said applicable law, it shall be 
construed, interpreted and limited to effectuate its purposes to the maximum 
legally permissible extent.  If it cannot be so construed and interpreted so 
as to be valid under such law, such provision shall be ineffective to the 
extent of such invalidity or prohibition without invalidating the remainder 
of such provision or the remaining provisions of this Agreement, and this 
Agreement shall be construed to the maximum extent possible to carry out its 
terms without such invalid or unenforceable provision or portion thereof.

     5.12 SEVERAL OBLIGATIONS.  All duties and obligations of each party to 
this Agreement shall be several and not joint.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be 
duly executed as of the date first above written.

   CUPERTINO BANCORP


By:___________________________
   C. Donald Allen, President


MID-PENINSULA SHAREHOLDERS

/s/ Duncan L. Matteson
________________________________            __________________________________
Duncan L. Matteson                          Owen D. Conley


                                            /s/ Donald L. Hammond
________________________________            __________________________________
Edwin E. van Bronkhorst                     Donald L. Hammond

                                            /s/ R. Hewlett Lee, M.D.
________________________________            __________________________________
Warren R. Thoits                            R. Hewlett Lee, M.D.


/s/ David L. Kalkbrenner                    /s/ Helen C. Leong
________________________________            __________________________________
David L. Kalkbrenner                        Helen C. Leong


/s/ Murray B. Dey
________________________________            __________________________________
Murray B. Dey                               George M. Marcus


/s/ Lawrence A. Aufmuth
________________________________            __________________________________
Lawrence A. Aufmuth                         Donald H. Seiler


________________________________            __________________________________
John F. Blokker                             Bruce E. Van Alstyne


/s/ Allan F. Brown                          /s/ Carol H. Rowland
________________________________            __________________________________
Allan F. Brown                              Carol H. Rowland

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