The site of the Soviet Embassy on 16th Street NW would be renamed "Andrei Sakharov Plaza" in protest of Soviet treatment of the dissident scientist, if an amendment adopted yesterday by the Senate Appropriations Committee becomes law.

The proposal, offered by Sen. Alfonse M. D'Amato (R-N.Y.), was an alternative to a House-passed recommendation that the block of 16th Street in front of the embassy between L and M streets NW be renamed for Sakharov.

District of Columbia officials had opposed the House recommendation because District policy specifies that only persons who have been dead at least two years are eligible for the honor of having city streets named for them.

The State Department opposed the street renaming as a violation of the Vienna Convention on Diplomatic Relations to prevent impairment of the dignity of foreign missions, but the Senate committee rejected that argument.

Sakharov, a Nobel prize-winning physicist, has been reported on a hunger strike in the Soviet Union in an attempt to get medical treatment for his wife, Yelena Bonner, in the West.

"It is a most fundamental and eloquent means that we in Congress can use to express our concern for . . . Andrei Sakharov and the millions he represents," D'Amato said in offering his amendment.

"Every piece of mail the Soviets get will remind them that we want to know what has happened to the Sakharovs," he said.

Sen. Arlen Specter (R-Pa.), chairman of the D.C. Appropriations subcommittee, said D.C. Mayor Marion Barry had no objections to the amendment, which now goes to the full Senate.