The Kennedy Center has set up a new advisory commission to find out, among other things, why more blacks don't attend its plays, concerts and shows.

That will be one question studied by an 18-member national committee seeking ways to expand black participation in the audiences, performances and staff of the Kennedy Center.

"There is a lack of blacks coming to performances. We want to know why . . . how the blacks perceive their welcome at the Kennedy Center . . . setting a climate in a collective sense," explained Archie L. Buffkins, who heads the newly formed commission.

Buffkins is assistant dean for graduate studies at the University of Maryland campus at College Park and has been a minority affairs consultant at the Kennedy Center.

At a press conference yesterday, Roger L. Stevens, the Center chairman, stressed the Kennedy Center must remain dedicated to bringing "high-quality" performances while looking for ways to expand its scope and constitutency, with special outreach to black Americans.

"What makes the difference is what's on stage - a quality product," Stevens said.

Questions at the press conference yesterday foreshadow the probability that the new commission will be touching on some sensitive areas, such as the Kennedy Center's ticket prices, its responsibility to help struggling artistic troupes and its programming.

One function of the commission, Buffkins indicated, will be to serve as a kind of national talent-alert network to seek the best in black community and experimental troupes of musicians, actors, dancers and other performers.

Many blacks cultural institutions are struggling with financial troubles, Buffkins noted, and can use technical and professional advice from the Kennedy Center. But the Center cannot be expected " to jump out as an octopus and bring up the quality of all these," he added.

Stevens said the Kennedy Center would make "every effort" for such groups "to be seen" but has to remember its dedication to quality as a national institution for the performing arts.

Stevens and Buffkin agreed that special discount tickets are not the answer to bringing more blacks to the Kennedy Center.

"I would like to make it clear that black people are willing to pay the same price as other people," Buffkins bristled when a questioner suggested more discount tickets be made available for blacks.

"Anything people want to consume they are willing to pay for . . . I don't want it to go around that blacks (don't come because they won't get off a nickel (for culture)."

Pointing to the thousands that fill Kennedy Stadium at $10 to $25 a head for rock concerts, Stevens wryly observed that "somebody is able to afford it." The facts of economic life, he said, are that ticket prices can't be cut because the Kennedy Center must pay its own, way since it receives no government subsidy and must meet high labor and production costs.

"The Center has sought since its inception to present programming that encourages black participation in terms of both performers and audience, including children," Stevens said. ". . . The Center has had some success in this effort. But we would like to do even more."

Buffkins emphasized that the new commission will not only be national in scope but will take on an international reach because of "the Third World" countries. He said he would be consulting with embassies of these countries on groups that might perform at the Kennedy Center.

Buffkins talked as if much of the commission work will be as a research group.It will hold forums in various regions of the country, with performers, educators and arts leaders talking about what blacks want in the arts. There will be a nation-wide mini-questionaire of such opinion and also informal polls among blacks on why they don't come to Kennedy Center performances.

The commission will explore ways that blacks can be drawn to the Kennedy Center by such new projects as the children's arts series, the musical theater laboratory and the Studio Theater, which will provide a 500-seat facility for new and experimental talent in music, theater and the dance.

One "very touchy issue," Buffkins said, will be the representation of blacks on the Kennedy Center administrative staff.

"No just at the usher level. We're talking about upstairs . . . As far as administering the program day-by-day, it [the profile of blacks] does not look good."

Stevens said the Center probably would be hiring a black comptroller in a few days. He would replacen a black predecessor, who left the Kennedy Center to go to the White Hosue.

As for the Board's trustees, Stevens said, they were appointees of the President and Steven's last recommendation had been Ralph Ellison, the black novelist, who just completed his term.