**EXHIBIT 31.1**

**CERTIFICATIONPURSUANT TOSECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

I, William M.Caldwell, IV, certify that:

(1)   I havereviewed this Quarterly Report on Form 10-QSB of Advanced CellTechnology, Inc.;

(2)   Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

(3)   Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the small business issuer asof, and for, the periods presented in this report;

(4)   The smallbusiness issuer’s other certifying officer(s) and I are responsible forestablishing and maintaining disclosure controls and procedures (as defined inExchange Act Rules 13a-15(e) and 15d-15(e)) for the smallbusiness issuer and have:

(a)    Designedsuch disclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the small business issuer, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

(b)   [Notapplicable];

(c)    Evaluatedthe effectiveness of the small business issuer’s disclosure controls andprocedures and presented in this report our conclusions about the effectivenessof the disclosure controls and procedures, as of the end of the period coveredby this report based on such evaluation; and

(d)   Disclosedin this report any change in the small business issuer’s internal control overfinancial reporting that occurred during the small business issuer’s mostrecent fiscal quarter (the small business issuer’s fourth fiscal quarter in thecase of an annual report) that has materially affected, or is reasonably likelyto materially affect, the small business issuer’s internal control overfinancial reporting; and

(5)   The smallbusiness issuer’s other certifying officer(s) and I have disclosed, basedon our most recent evaluation of internal control over financial reporting, tothe small business issuer’s auditors and the audit committee of the smallbusiness issuer’s board of directors (or persons performing the equivalentfunctions):

(a)    Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the small business issuer’s ability to record, process,summarize and report financial information; and

(b)   Any fraud, whether or not material, thatinvolves management or other employees who have a significant role in the smallbusiness issuer’s internal control over financial reporting.

| Dated: May 15, 2007 |   | /s/ WILLIAM M. CALDWELL, IV |
|--------------------------|--------|-----------------------------|
|                     |   | William M. Caldwell, IV     |
|                     |   | Chief Executive Officer     |

 

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