EXHIBIT A

                           PROMISSORY NOTE SECURED BY
                                 PLEDGE OF STOCK


                                 March 30, 1998

Cupertino, California                                                   $900,000


                                FIVE - YEAR NOTE


      The undersigned, Michael J. Anderson, for value received, promises to 
pay to Mission West Properties (the "Company") or any person or entity to 
whom this Note has been endorsed for payment, or order (collectively the 
"Holder"), the principal sum of Nine Hundred Thousand Dollars ($900,000) (the 
"principal sum") and interest on the principal sum from time to time 
remaining unpaid hereon from the date of this Note until paid in full at the 
rate of percent (5.59%) compounded annually. Subject to the provisions of 
Sections 3 and 5 of this Note, interest shall be paid annually on each 
anniversary of the date of this Note; the principal sum and any accrued but 
unpaid interest to be paid in full on or before the fifth anniversary of the 
date of this Note.

      Principal and interest will be paid in lawful money of the United 
States of America at the address of the Holder of this Note as shown on the 
books of the Company. The undersigned shall have the right to prepay all or 
any portion of the indebtedness represented hereby without premium or penalty 
upon ten (10) days notice.

      The  following is a statement of the rights of the Holder of this Note 
and the conditions to which this Note is subject, to which the Holder hereof, 
by the acceptance of this Note, agrees:

1. ATTORNEYS' FEES. If the indebtedness represented hereby is not paid in 
full when due, the undersigned promises to pay all costs of collection, 
including, but not limited to, reasonable attorneys' fees.

2. REPLACEMENT.  On receipt of evidence reasonably  satisfactory to the 
undersigned of the loss, theft, destruction or mutilation of this Note and, 
in the case of loss, theft or destruction, on delivery of an indemnity 
agreement or 


bond reasonably satisfactory in form and amount to the Company and the 
undersigned, or in the case of mutilation, on surrender and cancellation of 
this Note, the undersigned, at his expense, will execute and deliver, in lieu 
of this Note, a new Note of like tenor.

3. RIGHT TO ACCELERATE PAYMENT. This Note shall become immediately due and 
payable in the full amount of the principal sum then unpaid, together with 
all accrued and unpaid interest thereon, at the option of the Holder of this 
Note without notice or demand, upon the occurrence of any of the following 
events:

     (a) the undersigned becomes insolvent in that either a petition is filed 
     by or against the undersigned under any bankruptcy law, or he is unable 
     to pay his debts as they fall due, or he makes a general assignment for 
     the benefit of his creditors or takes any other action to take advantage 
     of any insolvency laws; or

     (b) the undersigned fails to make payment when due of any part or 
     installment of principal or interest, and such default is not cured 
     within ten (10) days of the Holder's giving notice of such default to 
     the undersigned; or

     (c) the election by the Company to accelerate payment of the Note 
     pursuant to Section 1(b) of the Restricted Stock Purchase Agreement of 
     even date herewith (the "Stock Purchase Agreement") between the Company 
     and the undersigned; or

     (d) any default by the undersigned under the terms of the Stock Purchase 
     Agreement or the Security Agreement (described below) which is not 
     otherwise specified in paragraphs (a), (b) or (c) above.

4. MODIFICATION. This Note and any of its terms may be changed, waived or 
terminated only by a written instrument signed by the party against which 
enforcement of that change, waiver or termination is sought.

5. SECURITY. This Note is given pursuant to the terms of the Restricted Stock 
Purchase Agreement and is secured under the terms of a Security Agreement of 
even date herewith made between the undersigned and the Company. The Holder 
shall be entitled to all the benefits of the security as provided in the 
Security Agreement, provided that the Holder shall not be obligated to 
proceed first against the collateral, but may proceed directly on this Note. 
In the event the Holder proceeds against the collateral and the proceeds of 
same are inadequate to pay any amounts due on this Note, the undersigned 
shall remain liable for any deficiency. Upon the occurrence of certain events 
stated in the Security Agreement and in the Stock Purchase Agreement, the 
entire amount of this Note may become payable prior to the maturity date 
stated herein.

6. GOVERNING LAW. This Note shall be governed by and construed and enforced 
in accordance with the laws of the State of California without regard to any 
principles governing conflicts of laws.

7. NOTICES. All notices and other communications required or permitted 
hereunder shall be in writing and shall be deemed effectively given upon 
personal delivery or on the day sent by facsimile transmission if a true and 
correct copy is sent the same day by first class mail, postage prepaid, or by 
dispatch by an internationally recognized express courier service, or at such 
other address as any party may designate by ten (10) days' advance written 
notice to the other party.

8. SEVERABILITY. If any provision of this Note should be found to be invalid 
or unenforceable, all other provisions shall nevertheless remain in full 
force and effect to the maximum extent permitted by law.




                                    Michael J. Anderson


                                    Address: 858 Fielding Drive
                                             Palo Alto, CA 94303