Exhibit
12.1




CERTIFICATION




I, David
Allan, certify that:




1.           I
have reviewed this annual report on Form 20-F of YM BioSciences
Inc.;




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 annual report, fairly present in all material respects the
financial condition, results of operations and cash flows of the issuer as of,
and for, the periods presented in this report;




4.            
The issuer’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 control over financial
reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))
for the issuer 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 issuer, 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)          
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 issuer’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 issuer’s internal control over financial reporting
that occurred during the period covered by the annual report that has materially
affected, or is reasonably likely to materially affect, the issuer’s internal
control over financial reporting; and




5.            
The issuer’s other certifying officer(s) and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
issuer’s auditors and the audit committee of the issuer’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 issuer’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 issuer’s internal control over financial
reporting.




Date:
      March 3, 2010
            By:
            /s/
      David G. P. AllanDavid
      G. P. AllanChairman
      and Chief Executive Officer