Exhibit 31.1 CERTIFICATION OF THE CHIEF EXECUTIVE
OFFICER Pursuant to Section 302 of the Sarbanes-Oxley Act of
2002 I, Jack H. Webb, hereby certify that: 1.
I have reviewed this annual report on Form 10-K of
  Alliance Financial Corporation;2.
Based on my knowledge, this annual 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 annual 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 registrant as of, and for, the periods presented in this annual
  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 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 annual 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 our
  conclusions about the effectiveness of the disclosure controls and
  procedures, as of the end of the period covered by this annual report based
  on such evaluation; andd)
disclosed in this annual report any change in the
  registrants internal control over financial reporting that occurred during
  the registrants fourth fiscal quarter that has materially affected, or is
  reasonably likely to materially affect, the registrants internal control
  over financial reporting;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: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. Dated: March 13, 2007 /s/ Jack H. WebbName: Jack H. WebbTitle: Chairman of the Board, President and Chief
  Executive Officer