The traditional barriers that have barred blacks from high ranking positions in the military are beginning to crumble, said Lt. Gen. Arthur J. Greeg, of the U.S. Army.

Greeg, who is black, spoke to about 100 persons last last week at the commissioning of 18 area college students in the U.S. Army Reserve Officers Training Program (ROTC). The ceremonies were held at the Fort McNair Officer's Club. Most of the 18 students, all commissioned as second lieutenants, are black.

"Statistically, 29.2 percent of the enlisted members, 24 percent of the non-commissioned officers and 6.8 percent of the commissioned officers (in the military) are black," Greeg said.

There are three black Army colonels scheduled for promotion to brigadier general later this year, Greeg said. He added that the Army now has 760 black officers- 191 Colonels and 571 lieutenant colonels - "which is a significant increase from earlier years."

Women also have benefited by the recent military efforts to provide equal opportunities, Greeg said.

"The number of women (in the Army) has increased sharply since the draft ended," he said, "rising from less than 4 percent in 1973 to nearly 7.6 percent in 1979.

"Although the number of women involved is still relatively small (56,611), the mold has been broken and the total number is expected to increase substantially."

Of the 18 ROTC cadets commissioned last week, five were women.

Greeg said military efforts to provide equal opportunities must be continued to provide more representation of blacks and women. He said programs at West Point and ROTC are ways of accomplishing the task.

The ROTC program provides college students from area campuses with military training and cash stipends while they attend classes. Although the program is offered only at Howard University and Georgetown University in the District, students from other schools may participate.

Most of the 18 students commissioned last week, according to Howard University ROTC spokesman Capt. Wilson Baker, plan to join the Army Reserve. He said many of the students have opted for early commissions under a special program so they can begin formally participating in the military while still being enrolled in classes.

All 18 students who received their commissions attended the Howard University ROTC program.

Michael Scruggs, 21, of Bowie State College, said he is so anxious to begin his military career that he has opted for an early commission.

"I really like the organization, it has a lot to do with management. It is not because I'm patriotic because we are not at war. I just like the military."

Scruggs, who said he will join the National Guard, said he will be involved in field artillery training.

Another newly commissioned second lieutenant, Diane Harley, 22, of Catholic University, said: "I have always been interested in organization. I haven't decided yet whether or not I am going to make a career of it, but I figure I will try it out."

Harley said she plans to join the military police in the active Army when she graduates next year.

The 16 other newly commissioned second lieutenants include: Virginia Boyd, Gregory Bolden, Clement Goowine, all of University of the District of Columbia; Kevin Kille, of American University; Johnny Manson, Aaron Pharr, Wayne Adams, Sharon Gresham, Marilyn Bridgette, Donald Myers, all of Howard University; Michael Shipp, Lewis Chapman, Terry Glass, Cheryl Mann, Ervin McBride, all of Bowie State College, and Steven Wabnitz, of University of Maryland. CAPTION: Picture, Newly commissioned ROTC 2nd Lt. Virginia Boyd, of the University of the District of Columba, receives her first official salute from Sgt. Maj. Jewell Edmonds. By John Dwyler for The Washington Post