**Exhibit
      31.1**


**Certification
      Under Section 302**





I,
      Noah
      Berkowitz, certify that:




1.
      I have
      reviewed this quarterly report on Form 10-Q of Alteon Inc.;




2.
      Based
      on my knowledge, this quarterly 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 quarterly
      report;




3.
      Based
      on my knowledge, the financial statements, and other financial information
      included in this quarterly 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 quarterly report;




4.
      The
      registrant’s other certifying officers 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 control 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, including its consolidated subsidiaries, is made known to us by
      others within those entities, particularly during the period in which this
      report is being prepared;




b) omitted
      paragraph pursuant to SEC Release
      Nos. 33-8238 and 34-47986;




c) evaluated
      the effectiveness of the
      registrant’s disclosure controls and procedures and presented in this report our
      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; and




d) 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 (the registrant’s fourth fiscal quarter
      in the case of an annual report) 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 officers 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 the registrant’s board of
      directors (or persons performing the equivalent function):


a)
          all
          significant deficiencies and material weakness in the design or operation
          of
          internal controls over financial reporting which are reasonably likely
          to
          adversely affect the registrant’s ability to record, process, summarize and
          report financial information; and




b)
      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.




Date:
                August 14, 2006
            
            
            
            By:
            
            /s/
                Noah BerkowitzNoah
                Berkowitz, M.D., Ph.D.
              President
                and Chief Executive Officer
              (principal
                executive officer)