Exhibit 31.1

** **

**Certifications**

 

I, Stephen G. Snyder,certify that:

 

1.                                       I have reviewed this annual report on Form 40-Fof TransAlta Corporation;

 

2.                                       Based on my knowledge, this report doesnot contain any untrue statement of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

 

3.                                       Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the issuer as of, and for, the periods presented in thisreport;

 

4.                                     The issuer’s other certifying officer(s) andI are responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and15d-15(f)) for the issuer and have:

 

a)                                      Designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to theissuer, including its consolidated subsidiaries, is made known to us by otherswithin those entities, particularly during the period in which this report isbeing prepared;

 

b)                                     Designed such internal control overfinancial reporting, or caused such internal control over financial reporting tobe designed under our supervision, to provide reasonable assurance regardingthe reliability of financial reporting and the preparation of financialstatements for external purposes in accordance with generally acceptedaccounting principles;

 

c)                                      Evaluated the effectiveness of the issuer’sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation; and

 

d)                                     Disclosed in this report any change inthe issuer’s internal control over financial reporting that occurred during theperiodcovered by the annual report that has materially affected, or isreasonably likely to materially affect, the issuer’s internal control overfinancial reporting; and

 

5.                                       The issuer’s other certifying officer(s) andI have disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the issuer’s auditors and the audit committee of theissuer’s board of directors (or persons performing the equivalent functions):

 

a.                                       All significant deficiencies and materialweaknesses in the design or operation of internal control over financialreporting which are reasonably likely to adversely affect the issuer’s abilityto 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 theissuer’s internal control over financial reporting.

 

Dated:           March 13, 2008.

 
|   | /s/ Stephen G. Snyder                  |
|--------|----------------------------------------|
|   | Stephen G.  Snyder                     |
|   | President and  Chief Executive Officer |