Chief Justice Warren E. Burger proposed yesterday that the nation devote three years to "serious rethinking" of the roles each of the three branches of the federal government.

The study would be an observance of the 200th anniversary of the Constitution in 1987. It would begin in 1985. A year each would be set aside for the legislative, executive and judicial branches, although a portion of the final year would be "perhaps devoted to an overview of all that has been discussed," Burger said.

The result could be "a series of papers comparable in utility if not in quality with the Federalist Papers of 200 years ago," he said.

Burger, who unveiled the proposal in a talk at the National Archives, said that the Judicial Conference of the United States, the administrative organization of the federal court system, has authorized him to appoint a special commission to prepare for the bicentennial observance.

"If we use the lead time now available to us we can develop a program worthy of the importance of the occasion," Burger said in incomplete excerpts of the talk released by the Supreme Court press office.

He suggested that 1985 be dedicated to a discussion of article I of the Constitution, which concerns Congress; 1986 to Article II, which concerns the executive, and 1987 partially to Article III, which concerns the judiciary.

All three branches have evolved "in ways unforeseeable two centuries ago," Burger said. The "rethinking" is necessary in the light of the intentions of the Founding Fathers and of the developments of two centuries," he said.

He noted that it cost $5.1 million to operate the entire federal government in 1792, a figure he contrasted with $53.7 million to run the local government of Colorado Springs in 1977. Capitol Hill staffs now number about 16,500 the executive branch employs 3 million people exclusive of the armed forces, and support personnel in the federal judiciary totals nearly 9,400 exclusive of probation officers, he said.