FOR THE LAST 10 years, Eileen Southern has been the only Black woman holding a lifetime post at Harvard. Bearing this unique distinction, Southern says, has been both a rewarding and, to some extent, a lonely experience.

At the end of next term, the professor holding joint tenure in music and Afro-American studies will retire. Her departure, on a pragmatic level, will leave the University without a scholar in ethno-musicology; more symbolically, it will strip the small female contingent within the Faculty of Arts and Sciences of any senior Black presence.

The Chicago native, who came from the City University of New York in 1976 to become chairman of the then-troubled Afro-American Studies Department, reflects upon her years here as intellectually exhilarating. But, she says, she has found that Harvard does not have a particularly positive attitude toward minorities, and believes the climate has grown colder since the early 1970s.

Southern gives the 1960s civil rights movement credit for making her Harvard appointment possible, and she feels fortunate to have been able to work at the University and to serve as a "role model" for other women on the faculty.

Still, Southern says, she has only now found her "niche" at Harvard. "I had a difficult time at first because I don't look like a Harvard professor. I don't wear thick-soled shoes; I don't have gray hair; I don't smoke; and I don't even look like a typical woman professor because they are supposed to have white skin and short haircuts, and a gray streak here and there."

She says she has given up nearly all social events she once tried to frequent. "I find it very difficult to interact with people during the cocktail hours. I'm usually the only Black person there and the only woman." She says she does not know whether the alienation she feels stems from her racial affiliation or her gender.

Southern says both problems probably contributed to her sense of distance. She is one of roughly 25 tenured women in a faculty of some 350 and one of four tenured Blacks.

"When I came here, I thought I would have these long, intellectual, exciting conversations with scholars in my field. And it has not turned out that way. I have had exciting conversations with maybe one or two people--males. I really miss the opportunity to interact with female scholars. I wonder what happens to all the other tenured women."

HARVARD HIRED SOUTHERN at a time when Afro-American Studies--instituted in the wake of militant student demands during the late 1960s--was suffering from plummeting student interest and the University's admitted inability to lure scholars to bolster the field.

She left New York for Boston, and committed herself to 10 years of commuting between the two cities. Southern's husband of 44 years, Joseph, a 66-year-old now-retired professor of accounting and computer science, could not leave his tenured post at CUNY to accompany his wife. They have shared the five-hour drive every weekend and talked on the phone each night since 1976.

Upon her arrival, Southern assumed the chairmanship of the Afro-American Studies Department. Says DuBois Professor of History and Afro-American Studies Nathan Huggins: "She helped hold the department together through some very difficult times."

Three years later, in 1979, the department celebrated its 10th birthday. But the celebration was not a merry one. Since 1971, the number of concentrators had dropped 76 percent, and the department had become the target of widespread student and junior faculty dissatisfaction.

In addition, the department was embroiled in a still unresolved racial discrimination suit filed by a junior professor. Then-Dean of the Faculty Henry Rosovsky, at the time, summarized the hiring situation with the following words: "We have failed. You've got to believe me when I say we tried--and we failed."

That spring, Southern took a semester-long sabbatical. While she was away, a group of junior faculty met with Rosovsky to voice their dissatisfaction with her performance as chairman. At the same time, in a series of demonstrations, which included a day-long boycott of classes, students charged the administration--and Rosovsky in particular--with a systematic campaign to destroy the department.

In response, Rosovsky created a five-member executive committee, made up of Southern and four other senior faculty members not connected with Afro-American Studies. The committee was assigned the tasks of "defining a sense of intellectual mission for the department," guiding and making key policy decisions, and aggressively recruiting scholars for tenured positions.