Susan Belford, a counselor at Gaithersburg High School, will again attend to about 300 students this year. That is already too many, but her work does not stop there.

She supervises the school's peer mediation program--helping students work out their disputes without being hauled in front of the principal. She conducts two discussion groups for students whose parents are divorcing and want to share thoughts on dealing with anger and disappointment.

On top of all that, there is the usual college application frenzy. She must make sure seniors meet their deadlines this fall, and then must introduce juniors to the process next spring. She is struggling with the school's new computer system--"it is like studying Greek," she said--and knows many of this year's seniors will drown her and her colleagues with applications for as many as a dozen different universities.

In an era in which the personal problems of adolescents seem more daunting than ever and in which many families are obsessed with college admissions, high school counselors like Belford have acquired a unique importance--as well as multiple responsibilities that may be stretching them too thin, some experts say.

Students do not see them frequently. There are usually no more than a half dozen of them in any high school. But when they do talk to students, the consequences of those few minutes of conversation can be immense.

Good counselors have helped people find the colleges or the jobs that changed their lives. Bad counselors have kept eager students out of challenging courses and squashed, with just a few discouraging words, youthful ambitions that might have led to fine careers.

"Guidance counselors have had a very powerful effect on important decisions that kids make in terms of their future," said Fred S. Evans, Gaithersburg High principal.

"They serve as surrogate parents for many of our students, someone who is warm, open and willing to take that extra step to find any type of service that the student may need," said Barbara Childs, assistant principal at Cardozo High School in the District.

Nick Smith, a recent graduate of Lee High School in Fairfax County, said he was particularly grateful for his counselor's help in getting through the complicated and stressful process of seeking financial aid for college. "They had a lot of information that I would not normally be able to find," he said. As a result, he is beginning his second year at Washington and Lee University in Lexington, Va.

Counselors are being asked to do many duties and need far more attention than they are getting, according to national experts. Joyce Smith, executive director of the Alexandria-based National Association of College Admissions Counselors, said her organization is concerned about "the aging population of most public school counselors, the fact that they are predominantly female and predominantly white . . . and although they update their credentials, they received their initial training 25 or 30 years ago."

She added: "These factors are important because there is growing diversity in the student population, racially, economically and academically. Most students and parents seek to have counselors who understand the changing diversity and address it through good counseling for college, careers and academic course placement."

Among the most important new tasks for counselors are overseeing state and national examinations and ensuring fair treatment of students with disabilities.

April Faw, the director of guidance at George Mason High School in Falls Church, worked last year at a North Carolina school "where half of my job was serving as a testing coordinator." That is not likely to change much at her new job, because Virginia is following North Carolina's lead in creating a series of achievement tests.

Linda A. Hutchinson, guidance director at Yorktown High School in Arlington County, said she serves as her school's testing coordinator, which she calls "a huge responsibility." There are the usual SAT, Advanced Placement and Stanford 9 achievement tests. But now, all Virginia high schools must give Standards of Learning (S0L) tests in 11 different subjects, and by 2004 students must pass six of those tests to graduate.

For every one of these tests, Hutchinson said, "I have to organize the testing or where it is done, who is doing all the test security and make arrangements for accommodations for students with disabilities."

While they organize the tests, prepare the college recommendations and perform the other routines of their jobs, counselors must keep an eye on their students, particularly those who seem lost or disturbed. The series of violent episodes at schools in recent years involving disenchanted students has given this role particular weight.

Faw, at George Mason, said she tries to be out in the halls between classes and at after-school activities so that students grow accustomed to seeing her and can approach her whenever they feel like it. If she senses a child is in distress, "I can let them know I am there if they feel like talking," she said.

There is one bit of good news about good counselors: They are not as difficult to replace when they move or retire as good teachers are. There are relatively few counseling jobs, and in many cases the salaries are higher than those for teachers, although counselors are often expected to work extra days in the summer.

But the small number of counseling jobs also means extraordinary burdens on each person taking the assignment. "Everyone has a different expectation of the services that counselors need to provide," said Smith, of the College Admissions Counselors Association, whose group is sponsoring a symposium next year on the issue. "Counselors end up being the facilitators of lots of different relationships among many different partners. Given those demands, I don't think any counselor can expect to have meaningful one-on-one relationships with all the students that are assigned to them."

Policy makers should consider the harm that can come when counselors do not get the training they need and have too many students to handle, Smith said. Many students who need help are still not getting it, sometimes with tragic consequences. According to national figures, a high school with 1,500 students will have six counselors plus a guidance director.

"Counselors wish they could get better professional development to prepare them for their new responsibilities," Smith said, "and not just after a crisis situation."

CAPTION: Susan Belford, a counselor at Gaithersburg High School, works with one of her 300 students. She also supervises peer mediation groups.