**Exhibit 31.2**

 

**CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER**

 

(Pursuantto Rule 13a-14 of the Securities Exchange Act of 1934, as amended,

asAdopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002)

 

I, Brian M. Posner, certifythat:

 

1.             I have reviewed thisquarterly report on Form 10-Q of Pharmacopeia Drug Discovery, 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 quarterly report;

 

3.             Based on myknowledge, the financial statements, and other financial information includedin this quarterly report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this quarterly report;

 

4.             The registrant’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)) for the registrant and have:

 

a)             designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant is made known to us by others withinthose entities, particularly during the period in which this quarterly reportis being prepared;

 

b)            evaluated the effectivenessof the registrant’s disclosure controls and procedures and presented in thisreport our conclusions about the effectiveness of the disclosure controls andprocedures, as of the end of the period covered by this report based on suchevaluation; and

 

c)             disclosed in thisreport any change in the registrant’s internal control over financial reportingthat occurred during the registrant’s most recent fiscal quarter that hasmaterially affected, or is reasonably likely to materially affect, the registrant’sinternal control over financial reporting; and

 

5.             The registrant’sother certifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the registrant’sauditors and the audit committee of registrant’s board of directors (or personsperforming the equivalent functions):

 

a)             all significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adversely affectthe registrant’s ability to record, process, summarize and report financialinformation; and

 

b)            any fraud, whether ornot material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 

Date:  June 2, 2004

 
|   | /s/ Brian  M. Posner      |   |
|--------|--------------------------------|--------|
|   | Brian M.  Posner               |
|   | Vice  President, Finance       |
|   | (Principal  Financial Officer) |

 

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