Tyler Professor of Constitutional Law Laurence H. Tribe, who advocates a liberal interpretation of the constitution, testified yesterday before the Senate Judiciary Committee in support of Supreme Court nominee Anthony M. Kennedy.

Tribe told the committee that he considers Kennedy to be a moderate conservative, who is more liberal than Robert H. Bork, a former nominee for Justice Lewis F. Powell's seat.

Tribe, who was in Washington for most of the day yesterday, could not be reached for comment.

A leading constitutional law scholar, Tribe testified against Bork this fall and advised Judiciary Committee members on how to defeat the nominee. Bork lost his bid by a vote of 58-42 in October.

Tribe is the only Harvard law professor scheduled to testify before the committee.

Professor of Law Alan M. Dershowitz said yesterday that he was "flabbergasted" that Tribe testified in support of Kennedy. While Dershowitz said that he thought Kennedy might be the best candidate in terms of liberal interests that President Reagan will nominate, he added that this is not a rationale for testifying in favor of the candidate.

"I can understand why a Senator might vote for him. A Senator can't abstain from voting," said Dershowitz, who advised senators on how to defeat Bork. "But a citizen can abstain, and I think abstention may the proper course of action when a bad president names a mediocre nominee to an already bad court."

Dershowitz added that Tribe's testimony seemed unnecessary in light of the fact that Kennedy will probably be confirmed quickly.

Kennedy's membership in private clubs indicated his sexist bias and that the nominee has ruled against the rights of women, gays, Hispanics, Blacks, and criminal defendants, Dershowitz said. "Judge Kennedy leans heavily against the Bill of Rights," he said.

Assistant Professor of Government H.W. Perry Jr., an expert on Supreme Court politics, agreed that Tribe's testimony would have little effect on the confirmation vote, which he did not think would be close.

"His testimony could make a difference in how people perceive Judge Kennedy, however, and those people could include the general public or the Senators," Perry said. "For people who admire Professor Tribe's judgement, his testimony could help color their judgement of the candidate."