Exhibit 12.1

**CERTIFICATION****PURSUANT TO SECTION 302**

**OF THE SARBANES-OXLEYACT OF 2002**

 

I, Dr. Mor Amitai, certify that:

1.             I have reviewed this annual report onForm 20-F of Compugen Ltd.; 

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 company as of, and for, the periods presented in this report;

4.             The company'sother certifying officer and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e)and 15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the company and have: 

a.             designed such disclosurecontrols and procedures, or caused such disclosure controls and procedures tobe designed under our supervision, to ensure that material information relatingto the company, including its consolidated subsidiaries, is made known to us byothers within those entities, particularly during the period in which thisreport is being prepared; 

b.             designed such internalcontrol over financial reporting, or caused such internal control overfinancial reporting to be designed under our supervision, to provide reasonableassurance regarding the reliability of financial reporting and the preparationof financial statements for external purposes in accordance with generallyaccepted accounting principles;

c.             evaluated theeffectiveness of the company's disclosure controls and procedures and presentedin this report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this reportbased on such evaluation ; and 

d.             disclosed in this reportany change in the company's internal control over financial reporting thatoccurred during the period covered by the annual report that has materiallyaffected, or is reasonably likely to materially affect, the company's internalcontrol over financial reporting; and 

5.             The company's other certifying officerand I have disclosed, based on our most recent evaluation of internal controlover financial reporting, to the company's auditors and the audit committee ofthe company's board of directors (or persons performing the equivalentfunctions): 

a.             all significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the company's ability to record, process, summarize and report financialinformation; and 

b.             any fraud, whether or notmaterial, that involves management or other employees who have a significantrole in the company's internal control over financial reporting.

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\s\ Mor Amitai

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Title:President, Chief Executive Officer and Director

Date: February 28, 2005

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