EXHIBIT 99.906CERT



     CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
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     In  connection  with the  shareholder  report  of  American  Century  Asset
Allocation  Portfolios,  Inc.  (the  "Registrant")  on Form N-CSR for the period
ending January 31, 2008 (the "Report"), we, the undersigned,  certify,  pursuant
to Section 906 of the Sarbanes-Oxley Act of 2002, that:

     (1)  The Report fully  complies with the  requirements  of Section 15(d) of
          the Securities Exchange Act of 1934; and

     (2)  The  information  contained  in the  Report  fairly  presents,  in all
          material respects,  the financial  condition and results of operations
          of the Registrant.


Dated: March 31, 2008



                               /s/  Jonathan S. Thomas
                               ------------------------------------
                               Jonathan S. Thomas
                               President
                               (chief executive officer)



                               /s/  Robert J. Leach
                               -------------------------------------
                               Robert J. Leach
                               Vice President, Treasurer, and
                               Chief Financial Officer
                               (chief financial officer)