One of the nation's foremost authorities on Constitutional law and the Supreme Court, Martin M. Shapiro, will become a professor of Government at Harvard next summer.

Shapiro, who now teaches at the University of California at Berkeley, is taking the place of Robert G. McCloskey, Trumbull Professor of American History and Government, who died in the summer of 1970.

"Delighted"

Shapiro received his Ph. D. in Government from Harvard in 1961 after studying under McCloskey.

Arthur Maass, Thomson Professor of Government, said he was "delighted" with Shapiro's appointment. "He's clearly the best man available."

Samuel P. Huntington, chairman of the Government Department, said he was delighted that Shapiro had agreed to accept the appointment. "There was no doubt in anybody's mind that he was number one," Huntington said yesterday.

Jesse Choper, visiting professor of Law from Berkeley, called Shapiro "extremely talented" and "a worthy successor to McCloskey."

In addition to teaching at Harvard and Berkeley, Shapiro has also served on the faculty of Stanford and of the University of California at Irvine.