When Mayor Marion Barry appeared last week at the 16th annual dinner of the predominantly black Howard University Law School alumni Association, he proudly trotted out the corporation counsel whose appointment he had announced only hours before, Judith W. Rogers.

Rogers is a fair-skinned black woman, who has been active with the Washington Bar Association, the major black lawyers' organization in town. Barry must have been concerned that some of the black lawyers would mistake Rogers for a white.

"If you're wondering," one person who attended the dinner recalled Barry saying as Rogers approacahed the microphone, "the answer is yes. She's one of us." That, observers said, quelled the uncertainties of many in the audience.

Taking the time to clarify Rogers'race was Barry's acknowledgement of the continuing importance of race in the politics of this overwhelmingly black town.

In his own words, Marion Barry thinks the future of black people running the city government is on the line with his administration.

"In 1975, right after home rule, there was a lot of skepticism on the part of white people and black people as to whether or not this government could be managed in general, and if it was going to be a majority black government, could it be done," Barry said in an interview last week.

In its first 100 days, Barry asserted, "this administration has demonstrated that it can be done in general and black people can do it in particular."

In deference to the political importance of race in this once staunchly segregated town, Barry's key advisers told the mayor at the beginning of his quest for a new corporation counsel that the city's chief legal eagle would have to be black.

(A black woman would be ideal, since Barry had received considerable support from feminists and was under pressure to appoint women to top posts in his administration.)

By statute, the corporation counsel is the third highest office in city government (below the mayor and city administrator). The corporation counsel's office, with its staff of nearly 90 lawyers, is a logical work place for many of the black lawyers breaking into the profession.

In a few years, moreover, the corporation counsel's office could well have the authority to prosecute local criminal cases now handled by the U.S. attorney's office here. The corporation counsel would then be the virtual attorney general of this city/state.

Before Rogers' appointment, there have been only three black corporation counsels, and one of those held the job on an acting status. Local black lawyers have for some time considered the number of black attorneys in the office in general and in upper level positions in particular to be far fewer than desired.

In 1977, reports that the number of blacks in the office had decreased sparked sharp criticism from a top official of the predominantly black Washington Bar Association. A suit alleging racial discrimination in the hiring and promotion of blacks was filed in the city Office of Human Rights. The office found "reason to believe" that such discrimination did exist.

Barry knows the importance of race in Washington politics. In the closing days of the 1978 Democratic campaign, for example, his advisers voiced strong concern to newspaper editors that photographs of Barry's wife Effi, who is black but fair-skinned, made it appear that Mrs. Barry is white. Those photographs prompted telephone calls to the campaign headquarters, the aides said, and it would be helpful if the newspaper would point out that Mrs. Barry is black..

After winning the primary, Barry used an Oct. 10 interview in the Washington Star to personally dispel the Effi-is-a-white-woman rumor: "There's a question,' says Marion Barry, looking distinctly abashed. 'You haven't raised it. I haven't raised it because it always comes up. That is what color Effi is.'"

Some felt it was perhaps more important for Barry to dispel such fears that it would be for some other politician because Barry, who won the critical Democratic primary with strong support from whites, has been suspiciously viewed by some blacks as the "white community's candidate."

Not only are many blacks in the city anxious to get into the high level government jobs held almost exclusively by whites, but some blacks believe that the recent increase in the District's white populaion is sounding an early death knell for the black prominence in local politics and government born out of home rule.

At an afternoon press conference announcing Rogers' appointment, Barry had played down the factor of race. Asked if Rogers was the first black woman to hold the post, he responded coyly, "she's the first woman."

At the Howard Law Alumni dinner, however Barry wanted the answer to the question to be crystal clear. "Now is a time when you don't want to waffle (on the question of race) because people consider race a factor," one Barry intimate said. "If he's going to waffle on it, how's he going to talk about affirmative action.