Two University of Maryland students and two College Park landlords have filed a lawsuit challenging a new Prince George's County zoning law that restricts student housing rentals.

The law requires houses with at least three unrelated students living in them to provide one parking space and a minimum 70-square-foot bedroom for each resident.

The lawsuit was filed Tuesday in Prince George's County Circuit Court by students Stephanie Stockman and Daniel Cones, president of the student government association, and College Park Property Owners Association members Donald Kirsch and Martha Kaye Dunn. The suit alleges that the zoning law discriminates against students and deprives landlords of rental income without compensation.

The law grew out of strained relations between students and full-time residents of the areas around the University of Maryland's College Park campus. Homeowners have complained about noise and parking problems created by students and argue that the proliferation of off-campus student housing lowers property values and diminishes a residential atmosphere.

Students say that because of a shortage of housing on campus, most students are forced to search for living quarters elsewhere. The new law, they said, will severely limit an already tight market.

Cones, a senior who lives off-campus with four other students, said as many as 3,000 students could be affected by the new law.

Property owners have until July 1, 1991, to comply.

Deputy County Attorney Michael Connaughton defended the law. "In zoning laws you are allowed to make distinctions based on certain classifications," he said. "The Supreme Court has upheld zoning laws that limit the number of people living in a home in a residential area. The law says 20 unrelated people cannot live in a house together, but if it's two parents and they are prolific and have 20 kids . . . well, that's legal."

Jim Kane, a member of the College Park Property Owners Association and manager of several area properties, said such distinctions cannot be allowed to become discriminatory. "The whole intent of all of this is to drive the students away from College Park, to satisfy a small group of people who absolutely abhor lifestyles that are different from their own," Kane said.