CERTIFICATIONS

                                                                                                                                               EX-99.CERT

I, Jonathan S. Thomas, certify that:

1.	I have reviewed this report on Form N-CSR of American Century Asset Allocation Portfolios, Inc.;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit
	to state a material fact necessary to make the statements made, in light of the circumstances under
	which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this
	report, fairly present in all material respects the financial condition, results of operations, changes in
	net assets, and cash flows (if the financial statements are required to include a statement of cash
	flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant's other certifying officer and I are responsible for establishing and maintaining
	disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act
	of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the
	Investment Company Act of 1940) for the registrant and have:
	(a)	Designed such disclosure controls and procedures, or caused such disclosure controls and
		procedures to be designed under our supervision, to ensure that material information
		relating to the registrant, including its consolidated subsidiaries, is made known to us by
		others within those entities, particularly during the period in which this report is being
		prepared;
	(b)	Designed such internal control over financial reporting, or caused such internal control over
		financial reporting to be designed under our supervision, to provide reasonable assurance
		regarding the reliability of financial reporting and the preparation of financial statements
		for external purposes in accordance with generally accepted accounting principles;
	(c)	Evaluated the effectiveness of the registrant's disclosure controls and procedures and
		presented in this report our conclusions about the effectiveness of the disclosure controls
		and procedures, as of a date within 90 days prior to the filing date of this report based on
		such evaluation; and
	(d)	Disclosed in this report any change in the registrant's internal control over financial
		reporting that occurred during the second fiscal quarter of the period covered by this report
		that has materially affected, or is reasonably likely to materially affect, the registrant's
		internal control over financial reporting; and

5.	The registrant's other certifying officer and I have disclosed to the registrant's auditors and the audit
	committee of the registrant's board of directors (or persons performing the equivalent functions):
	(a)	All significant deficiencies and material weaknesses in the design or operation of internal
		control over financial reporting which are reasonably likely to adversely affect the
		registrant's ability to record, process, summarize, and report financial information; and
	(b)	Any fraud, whether or not material, that involves management or other employees who
		have a significant role in the registrant's internal control over financial reporting.

Date: September 29, 2010

/s/ Jonathan S. Thomas

Jonathan S. Thomas

President

(principal executive officer)

I, Robert J. Leach, certify that:

1.	I have reviewed this report on Form N-CSR of American Century Asset Allocation Portfolios, Inc.;
2.	Based on my knowledge, this report does not contain any untrue statement of a material fact or omit
	to state a material fact necessary to make the statements made, in light of the circumstances under
	which such statements were made, not misleading with respect to the period covered by this report;
3.	Based on my knowledge, the financial statements, and other financial information included in this
	report, fairly present in all material respects the financial condition, results of operations, changes in
	net assets, and cash flows (if the financial statements are required to include a statement of cash
	flows) of the registrant as of, and for, the periods presented in this report;
4.	The registrant's other certifying officer and I are responsible for establishing and maintaining
	disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act
	of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the
	Investment Company Act of 1940) for the registrant and have:
	(a)	Designed such disclosure controls and procedures, or caused such disclosure controls and
		procedures to be designed under our supervision, to ensure that material information
		relating to the registrant, including its consolidated subsidiaries, is made known to us by
		others within those entities, particularly during the period in which this report is being
		prepared;
	(b)	Designed such internal control over financial reporting, or caused such internal control over
		financial reporting to be designed under our supervision, to provide reasonable assurance
		regarding the reliability of financial reporting and the preparation of financial statements
		for external purposes in accordance with generally accepted accounting principles;
	(c)	Evaluated the effectiveness of the registrant's disclosure controls and procedures and
		presented in this report our conclusions about the effectiveness of the disclosure controls
		and procedures, as of a date within 90 days prior to the filing date of this report based on
		such evaluation; and
	(d)	Disclosed in this report any change in the registrant's internal control over financial
		reporting that occurred during the second fiscal quarter of the period covered by this report
		that has materially affected, or is reasonably likely to materially affect, the registrant's
		internal control over financial reporting; and
5.	The registrant's other certifying officer and I have disclosed to the registrant's auditors and the audit
	committee of the registrant's board of directors (or persons performing the equivalent functions):
	(a)	All significant deficiencies and material weaknesses in the design or operation of internal
		control over financial reporting which are reasonably likely to adversely affect the
		registrant's ability to record, process, summarize, and report financial information; and
	(b)	Any fraud, whether or not material, that involves management or other employees who
		have a significant role in the registrant's internal control over financial reporting.

Date: September 29, 2010

/s/ Robert J. Leach

Robert J. Leach

Vice President, Treasurer, and

Chief Financial Officer

(principal financial officer)