TANOX INC
AM NO. 1 NON-EMPLOYEE DIRECTOR'S STOCK OPTION PLAN
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<TYPE>EX-10.1
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<FILENAME>dex101.txt
<DESCRIPTION>AM NO. 1 NON-EMPLOYEE DIRECTOR'S STOCK OPTION PLAN
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                                                                    EXHIBIT 10.1

                                AMENDMENT NO. 1
                                       TO
                 2000 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN


     THIS AMENDMENT by Tanox, Inc. (the "Company"),

WITNESSETH:
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     WHEREAS, the Company maintains the Tanox, Inc. 2000 Non-Employee Directors'
Stock Option Plan (the "Plan"); and

     WHEREAS, the Company retained the right in Section 12 of the Plan for the
Board of Directors of the Company to amend the Plan from time to time; and

     WHEREAS, the Board of Directors approved resolutions on May 16, 2001,
amending the Plan as set forth below;

     NOW, THEREFORE, the Company agrees that, effective June 1, 2001, the plan
is amended as follows, subject in all respects to the approval hereof by the
stockholders of the Company at the annual meeting of stockholders to be held in
2002 and no Option awarded hereunder may be exercised unless and until such
approval is granted:

     1.   Section 2 of the Plan is hereby amended to include the following new
          definition:

          "Black Scholes Value" means the value of an Option using the Black-
          Scholes valuation methodology determined either as of the date of the
          relevant grant of the Option or as used to value the most recent stock
          option grant made within the preceding twenty-four months under this
          or any other stock option plan of the Company.  The assumptions used
          to determine the Black Scholes Value and the date of valuation will be
          subject to approval by the Board.

     2.   Section 5 of the Plan is hereby amended to read as follows in its
          entirety:

     "5.  ELIGIBILITY.

          All Non-Employee Directors shall be eligible to participate in the
          Plan."

      3.  Section 6 of the Plan is hereby amended to read as follows in its
          entirety:

     "6.  NON-DISCRETIONARY GRANTS.

        (a) Initial Grant. After May 16, 2001, each person who is elected or
     appointed to be a Non-Employee Director for the first time automatically
     shall, upon
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     the date of his or her election or appointment, be granted an Option to
     purchase shares of Common Stock having a Black Scholes Value of $200,000 on
     the terms and conditions set forth herein.

        (b) Subsequent Grant. Beginning with the 2002 annual meeting of
     stockholders, each person who is a Non-Employee Director immediately
     following any annual meeting of stockholders of the Company at which
     Directors are elected, and who has not received a grant under Section 6(a)
     within the preceding six months, shall automatically be granted, on the
     date of such annual meeting, an Option to purchase shares of Common Stock
     having a Black Scholes Value of $80,000 on the terms and conditions set
     forth herein."

        IN WITNESS WHEREOF, the Company has executed this Amendment this 16th
day of May, 2001.


                                        TANOX, INC.


                                        By:   Michael A. Kelly
                                           ----------------------------------
                                        Name:  Michael A. Kelly
                                        Title: Vice President and CFO

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