Despite a national reputation for progressiveness on race issues, Montgomery County's schools have failed seriously to improve the academic performance of minority students, according to a new study by an independent committee of citizens and black organizations.

In a 34-page report released yesterday, titled a "Study of Children at Risk," the Citizen's Minority Relations Monitoring Committee of Montgomery County said minority students are underrepresented in advanced courses and suspended at a much higher rate than white students. Problems of minority students in the system have reached "crisis proportions," it said.

"The education of black and Hispanic children in Montgomery County public schools, especially those from low-income family circumstances, has become such a serious problem," the study said, "that in one sense it is difficult to understand why the parents of many students who are achieving so poorly are not up in arms individually if not collectively over the failure of the system to minimally prepare their children to be educationally competent people."

School board President Blair Ewing, who earlier this summer proposed a seven-step outline to narrow the gap between performances of minority and white students, said he agreed with the committee that the school system has been deficient in educating minority students, but disagreed with a committee conclusion that the board, strapped by the bureaucracy of the school system, would be unable to do something significant about the problem.

"It is very clear that we have not succeeded in the way we should have in educating minority students, in particular black and Hispanics," Ewing said, "but we are going to move on this one and we are going to make a change, a dramatic change."

Ewing said he understood the angry tone of the report, saying it reflected on actions taken during the preceeding four years by a board majority that was swept out of office last November. Among them was the abolition of the old Citizens Minority Relations Monitoring Committee, which was replaced by a broader-based group.

The current committee, comprised of representatives of several black fraternities and sororities and civic groups such as the League of Women Voters, called on the school system to make a massive effort to study why the county's 16,576 black and Hispanic students are lagging so far behind other students and, in particular, to begin immediately to correct problems experienced by black males.

The report called for the formation of a task force to correct the serious imbalance in minority suspensions. In the 1981-82 school year, for example, 16.7 percent of blacks and 7.9 percent of Hispanic students were suspended more than once, while 6.3 percent of whites and 2.4 percent of Asians had been similarly disciplined.

The disproportionate suspension of minority students also has been a problem in other area school districts. Earlier this year, for example, the Arlington schools reported that 19 percent of its black students had been suspended more than once, compared with 4 percent of whites.

The stinging attack on Montgomery's schools, often cited as among the best in the nation, noted that black and Hispanic students score around the 50th percentile on national California Achievement Tests while white and Asian students typically score in the 70th and 80th percentiles.

The report also noted that earlier this year two out of three black students and more than half of the Hispanics failed a state math skills proficiency test, while 70 percent of the whites and 77 percent of the Asian students passed the exam.

Last school year, blacks made up 13.3 percent of the system's 92,517 pupils, Asians 7.3 percent and Hispanics 4.6 percent.

The report commended the school system for acknowledging in a study that it had problems in identifying black and Hispanic students for courses for gifted and talented students, but said minority enrollment in those courses remains alarmingly low: In 1980-81, blacks made up 6 percent and Hispanics, 2 percent of those classes.

The report said those figures were so imbalanced that they might form the basis of a class-action lawsuit. Last year, the Prince George's County chapter of the NAACP submitted figures on black representation in courses for gifted and talented students as evidence of a failure to desegregate Prince George's County schools. In 1980, for example, blacks in Prince George's made up 49.9 percent of the county enrollment, but only 12.7 percent of the enrollment in courses for gifted and talented students.