POWER OF ATTORNEY


	The undersigned, Nancy T. Chang, an officer of Tanox, Inc., a Delaware
Corporation ("Tanox"), hereby designates John Blickenstaff and Katie-Pat Bowman,
and each of them, his true and lawful attorney-in-fact and agent, with full
power of substitution and resubstitution, for him and in his name, place and
stead, in any and all capacities, to sign any and all Forms 3, 4 and 5,
including amendments thereto, disclosing changes in his beneficial ownership of
securities and derivative securities of Tanox and to file the same with the
Securities and Exchange Commission, granting said attorney-in-fact and agent,
and any of them, full power and authority to do and perform each and every act
and thing requisite and necessary to be done in and about the premises, as fully
to all intents and purposes as he might or could do in person, hereby ratifying
and confirming all that said attorney-in-fact and agent, or any of them, or his
or their substitute or substitutes, may lawfully do or cause to be done by
virtue hereof. This power of attorney shall remain effective for so long as I am
subject to the reporting requirements of Section 16(a) promulgated under the
Securities Exchange Act of 1934 or until earlier revoked by the undersigned.



Date:  October 2, 2000                     Nancy T. Chang