In a move that has potentially explosive political fallout, Attorney General Benjamin R. Civiletti disclosed yesterday that he plans a major new look at whether local communities use zoning laws to discriminate against minorities in housing.

"There's a prospect that if we change our focus to planning, zoning and financing, we could bring suits that would have a substantial effect in breaking down the nooses around some of our major cities in fair-housing development in the suburbs," he told a group of Washington Post editors and reporters. "We've done very little of that. It's difficult to do."

Civiletti said he had "a very strong suspicion" that there has been deliberate use of land-use ordinances by some localities to exclude minorities, though he cautioned that his study of the problem is just beginning.

He said he envisions the department's civil rights division looking at communities where there are dramatic diferences between the minority populations of center cities and surrounding suburbs, and then examining the history of zoning changes in those suburbs.

He said this would "determine whether there is evidence that those zoning laws were intentionally manipulated or designed to prevent the development of minority housing or residential ownership by a substantial market in adjacent communities."

Civiletti said he hadn't disclosed his proposed shift in emphasis with President Carter yet because he wanted to wait to see if the department found the evidence to bring such cases.

Martin Sloane of the National Committee Against Discrimination in Housing said yesterday that he applauded Civiletti's new emphasis in the land-use area. "The whole area of litigation has lagged because the United States hasn't been a major actor," he said.

The reaction of some local officials to the new federal role might have been foreshadowed yesterday by Jack Herrity, a member of the Fairfax County Board of Supervisors. "Apparently the federal government doesn't have anything better to do but go around wasting taxpayers' money sticking its nose into other people's business," he said.

"It's a question of whether you believe in local government or believe the federal government should do everything," Herrity, a Republican, said. "Maybe the Carter administration is playing for the minority vote."

Charles Gilchrist, county executive in Montgomery County, another Washington suburb with a small minority population, said he wouldn't mind having federal officials take a look. "We've got a good record here, a variety of housing," he said.

He agreed with Herrity that land use and zoning are local issues, but added that "there's a line you cross where there's a national obligation to make sure the laws are enforced."

Low or moderate-income housing is a constant and volatile topic of interest in affluent suburban areas. For example, a hearing on a proposed project in Potomac, Md., last month drew 1,100 angry protesters to a hall seating 300, according to a county official. The county official recently voted down the idea.

There has been a reluctance at Justice in the past to pursue land-use cases, according to officials. Drew S. Days III, head of the Civil Rights Division, said he has been trying to shift more resources to such broader attacks on alleged discrimination. "I've been on that train since I've been here," he said.

In recent years, the Civil Rights Division has filed 300 fair-housing cases, but almost all have been against individual developers or apartment owners. "That just picks away at the edges of the problem," Days said.

The Justice Department has the authority to bring civil suits against "pattern and practice" of discrimination, such as zoning, under Title 8 of the Fair Housing Act, but has filed only two such cases since the law was passed in 1968, acording to Sloane.

One was years ago against Black Jack, Mo., a suburb of St. Louis. The current case is against Parma, Ohio, a city of 100,000 on the outskirts of Cleveland. It has 50 black residents, according to a Justice civil rights lawyer.

Days said there was no reluctance by the Carter administration to attack the sensitive issue of discrimination in suburban housing. "They're just hard cases," he said. "And it did take a while to overcome institutional inertia."

Several land-use investigations are under way, Days added.