Exhibit 31.2
 CERTIFICATION OF PRINCIPAL ACCOUNTING OFFICER
PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002
  1.
    
    I have reviewed this Quarterly Report on Form 10-Q of RXi Pharmaceuticals
Corporation;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 and 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 Exchange Act Rules 13a-15(e)
and 15d-15(e)) and internal controls over financial reporting (as defined in Exchange Act
Rules 13a-15(f) and 15d-15(f)) 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, 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 my conclusions about the effectiveness
of the disclosure controls and procedures, as of the end of the period covered by
this report based on such evaluation; andd)
    
    Disclosed in this report any change in the registrants internal
control over financial reporting that occurred during the registrants most recent
fiscal quarter 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, based on our most
recent evaluation of internal control over financial reporting, to the registrants
auditors and the audit committee of 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; andb)
    
    Any fraud, whether or not material, that involves management or other
employees who have a significant role in the registrants internal controls over
financial reporting.
 Dated:  August 16, 2010
    /s/ Amy B. TataAmy B. TataTreasurer and Controller