Virginia students scored higher than the national average for the second consecutive year on standardized tests, and 95 percent of the state's 10th graders passed the basic skills exam required for high school graduation, according to 1985 results released yesterday.

But the gap between the scores of blacks and whites persisted, although it has narrowed over the years. In 1985, 89.2 percent of Virginia's black 10th graders passed the minimum competency test, compared with 96.7 percent of whites.

Overall, Virginia's national percentile ranking on achievement and ability tests administered to 206,000 fourth, eighth and 11th graders showed students in the state holding their own or gaining slightly from last year, with Northern Virginia scores among the best in the state. Statewide scores ranged from the 52nd percentile on 11th grade social studies to the 68th percentile on eighth grade math. The national average is 50.

"These results are pleasing from the standpoint that they do show gain," Claude A. Sandy, Virginia's director of testing, said yesterday. "From the general results that we've released . . . I don't think there is any indication of any need for marked changes in curriculum."

The state Department of Education yesterday released results of two tests it requires all public schools to administer -- an ability and achievement series for fourth, eighth and 11th graders and a basic skills test for 10th graders that is required for high school graduation.

The 94.9 percent passing rate for the basic skills test taken by 66,208 10th graders dropped slightly from 1984's 95.3 percent, but "it's probably just a glitch," said Elaine P. Grainger, a state supervisor of testing. She said the statewide passing rate is so high she would be surprised if it rises in the future.

Northern Virginia scores on the ability and achievement tests, published by Science Research Associates, were comfortably above the national and statewide averages except in Alexandria. Scores for Fairfax and Arlington Counties had been released previously. Alexandria is scheduled to release detailed results today.

Alexandria has more low-income students than other area jurisdictions, and experts say family income is among the most important factors influencing a student's test score. Statewide scores, too, reflected the income level in the area.

On the minimum competency tests, Northern Virginia students had a pass rate as good as or better than the statewide average, except for Alexandria, where the 84.9 percent pass rate was among the lowest in the state.

On both the reading and math portions of the competency test required for graduation, Virginia's 10th grade girls had a slightly higher pass rate than boys -- 98 percent to 95.9 percent in reading and 96.8 percent to 96 percent in math.

Grainger said minority scores have improved since the competency test first was given in 1978, when only 58.2 percent of blacks passed, compared with 89.1 percent of whites. As blacks continue to move up the economic ladder, their scores will keep rising, she said.

Of the 4,550 11th graders who took the minimum competency test this year -- some of whom had failed it before, others of whom had just moved to Virginia -- 89.1 percent passed. Of the 474 seniors who took the test, 89.1 percent passed.

Ability and achievement tests are given for reading, math, use of language, social studies and science, as well as educational ability and ability to use reference materials.