An investigation of black parents' complaints of racism at South Lakes High School in Reston turned up no pattern of discrimination, but found some cause for concern, Fairfax County Superintendent Robert R. Spillane told a community meeting last night.

Spillane released a report by the school system's human relations office that was a response to a petition signed last fall by three dozen parents of current and former black students at the school, which has 300 blacks among its 2,200 students.

The petition charged that black students are not encouraged academically, that a racial double standard is used in discipline, that there are no black administrators and too few black teachers, and that black parents are treated as "troublemakers."

It also described an atmosphere of discrimination against and distrust of black students at the school.

The petition created a furor at the school when it was made public last month, and it raised troubling questions for many residents of Reston, a new town created two decades ago with the intention of housing a diverse population. Today $200,000 homes are situated near low- and moderate-income housing projects.

The school system report, released by Superintendent Robert R. Spillane, quoted extensively from a survey of students, parents and faculty members at the school that was not a scientific random sample. The report concluded that there are isolated problems at South Lakes, including scattered racist graffiti and racial slurs, and a disproportionate -- although not necessarily unjustified -- suspension rate for black male students.

Overall, "we do not have evidence that indicates a widespread pattern of racism at South Lakes High School," the report concluded.

"The issue is one of communication," Spillane said after spending an hour at the meeting. Asked whether the school system's report vindicates the school, Spillane replied, "There's always a problem . . . but I don't think it's a major one."

Spillane agreed to a demand by black parents for an independent committee to hear complaints not answered by the school system report.

Afterward, some parents said they were angry that Spillane had delegated the task of follow-up to school officials, rather than handling it himself, but two School Board members who attended the session -- Kohann H. Whitney and Frank Francois -- said that was appropriate. And some parents said gains had been made. "There's a recognition that there is a problem," said Darlene T. Palmer, an organizer of the black parents' group.

The report noted that there are no minority administrators at South Lakes, but it said that 11.5 percent of the teachers are from minorities, a figure higher than the county's affirmative action objective.

The report recommended that the school work more closely with students whose grades are substandard, that school policies be reviewed "to ensure consistency throughout the school," and that a campaign against litter be expanded to include elimination of racist graffiti.

The report also recommended that the committee Spillane agreed to create should, among its duties, "look into the underlying causes of behaviors which lead to the disproportionate suspension of black students, focused particularly on fighting, disruptive behavior and insubordination."