More than 250 demonstrators gathered yesterday at Boston's City Hall Plaza to protest measures to revive the draft. The House Military Personnel Subcommittee voted Monday to preliminarily adopt an amendment requiring the President to commence draft registration in 1981.

The House Armed Services Committee is expected to debate the amendment, requiring registration for all males who turn 18 after December 31, 1981, next week, before the legislation goes to the floor of the House, David Price, a staff member of the committee, said yesterday.

The Committee adopted the measure with a unanimous voice vote, but narrowly turned down another proposal that would have required induction of 200,000 men for Ready Reserve training.

David Landau, spokesman for the American Civil Liberties Union (ACLU), said yesterday the vote "was a signal that Congress is going to reinstitute draft registration," adding "you only register people if you're going to draft them."

Landau added that his organization, which has launched a major national campaign to stop the draft, objected to the amendment in part because it is tacked on to the military procurement act of 1978, the annual bill for defense spending. The two issues should be separated, he said.

At the Boston demonstration, organized by the Boston Alliance Against the Registration and Draft, speakers told protesters the move to reinstate the draft must be stopped before it can gain momentum.

Student organizers called on demonstrators to help lobby congressmen while others, including Robert Nozick, professor of Philosophy, told students to stand up for their "moral rights."

Nozick said the draft and compulsory service measures are a great threat to the rights of people "to do what they choose."

John Judge, a field worker for the Central Committee for Conscientious Objectors, said the movement to revive the draft is being hidden by the Defense Department. "They tell us we're going to have a registration and not a draft.' Do you get dressed up and not go out?" Judge asked the protesters.

Leda Cosmides '79, an organizer of the rally, said yesterday, "A lot of people aren't taking the draft seriously yet because it's an abstract thing."

Analysts in Washington said yesterday they expect that whatever legislation eventually passes both houses will probably include both males and females now between the ages of 19 and 21.

Richard C. Hunter, director of the Department of Defense's manpower office, said yesterday support in Congress for registration is coming from a group of Congressmen "who were the hawks in Vietnam, didn't want to provide amnesty, and didn't want to end the draft in the first place."