When Ralph and Edna Coleman moved out of Washington 27 years ago, they built a small white clapboard house for $7,000 in what was one of Fairfax County's small, isolated black communities.

Despite dramatic changes in the Northern Virginia suburbs, their neighbo rhood, Odricks Corner, remained stable, as it had since its founding in 1872 by a hanful of freed slaves.

Yesterday the Colemans and their neighbors stood on the lawn of a 90-year old house, pleading for public pressure to block state Highway Department officials from slicing their neighborhood with a huge highway interchange.

Coleman, now 70 and retired planted a small handletter sign in his front yard, reading "This Family May Be Displaced." If the highway comes, Coleman said, he had no idea what he and his wife would do. "we can't afford another house," he said, simply.

What threatens the community is a proposal to build a toll highway parallel to the nearby Dulles Access Highway. That road, approved by the Virginia legislature this year, calls for several highway interchanges along the Dulles highway, including one that Odricks Corner residents claimed would destroy their community.

"The community is small, but it is alive," said the Rev. Ronald Winter, pastor of the neighborhood's 106-year-old Shiloh Baptist Church. "many of the events over the past 100 years have brought a rich partnership of labor, love, prayer, and deep concern," he said. "We come this far because of the efforts of slaves and descendants of slaves who labored here . . . to build a community."

Officials of the Washington Urban League, a civil rights group, joined Winter, The Colemans and their neighbors yesterday to announce formation of a "Save Odricks Corner Task Force." Fairfax Supervisor John P. Shacochis, whose Dranesville District also includes the fashionable homes of nearby Mclean, said the proposed intersection is "supposed" to speed traffic in and out of the Tysons Corner shopping center.

But Shacochis said destruction of the community is too high a price to pay for the interchange, which would be built near the intersection of Lewinsville and Spring Hill roads near the planned Tysons II complex.

The Virginia Highway Department's resident Fairfax engineer, Donald Keith, said yesterday that no decision has been made about whether the interchange will be built as proposed. But that did not deter the protesters.

"It makes my heart sad that we are going to be uprooted by not a four-legged animal, but a two-legged animal (man)," said 80-year-old Mae Hall, whose home at8333 Lewinsville Road, overloks the community.

Hall will not lose her home to the proposed interchange, but she said Odricks Corner, where she has lived for 50 years, will be disbanded.

Augustus Lacey, who has been living nearby at 8340 Odricks Lane for 25 years, said his fears were in part economic. I don't want to be displaced . . . I can't get enough money out of this (present home) to go somewhere else," he said.

Blakely Weaver, who built several of the homes in the neighborhood, said after the Civil War about 1,000 acres of the land in the vicinity of the community was owned by blacks. Since then, he said, blacks have sold most of their land to developers and there are only 100 acres in the area still owned by blacks. "If the interchange is built, it will destroy what's left," he said.