Exhibit 5.1
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                  [LETTERHEAD OF BOND, SCHOENECK & KING, LLP]

February 5, 2001

Community Bank Systems, Inc.
5790 Widewaters Parkway
DeWitt, New York 13214

      Re: Community Bank System, Inc. / Registration Statement on Form S-4

Ladies and Gentlemen:

We have acted as counsel to Community Bank System, Inc., a Delaware corporation
(the "Company"), in connection with the preparation and filing of a registration
statement on Form S-4 (the "Registration Statement") under the Securities Act of
1933, as amended, covering an aggregate of 3,566,439 shares (the "Shares") of
common stock, no par value, of the Company to be issued pursuant to the merger
described in the Registration Statement (the "Merger").

As such counsel, we have examined the Registration Statement and the Agreement
and Plan of Merger, dated November 29, 2000, by and between the Company and
First Liberty Bank Corp., as amended (the "Merger Agreement"), relating to the
Merger, as well as such corporate records, certificates and other documents and
such questions of law as we have considered necessary or appropriate for the
purposes of this opinion. In rendering this opinion, we have (a) assumed (i) the
genuineness of all signatures on all documents examined by us, (ii) the
authenticity of all documents submitted to us as originals, and (iii) the
conformity to original documents of all documents submitted to us as photostatic
or conformed copies and the authenticity of the originals of such copies; and
(b) relied on (1) certificates of public officials and (2) as to matters of
fact, statements and certificates of officers of the Company.

Based on the foregoing, we are of the opinion that the Shares have been duly
authorized and, when issued to the holders of common stock, par value $0.3125
per share, of First Liberty Bank Corp. in accordance with the Merger Agreement,
the Shares will be validly issued, fully paid and non-assessable.

We are attorneys admitted to the Bar of the State of New York, and express no
opinion as to the laws of any jurisdiction other than the laws of the United
States of America and the State of Delaware.


We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the use of our name under the heading "Legal Matters" in the
proxy statement/prospectus forming a part of the Registration Statement. In
giving such consent we do not thereby concede that we are within the category of
persons whose consent is required under Section 7 of the Securities Act or the
rules or regulations promulgated thereunder.

Very truly yours,

/s/ BOND, SCHOENECK & KING, LLP