CINCINNATI (AP) _ Potential jurors in an obscenity trial involving Robert Mapplethorpe's sexually explicit photos were asked Monday whether they look at Playboy magazine or attend arts fund-raisers.

Many questioned during the first day of jury selection said they'd seen such adult magazines as Playboy, Penthouse and Hustler, but said they didn't subscribe. None acknowledged having taken an art class or attending a fund- raiser for the arts.

The Contemporary Arts Center and its director, Dennis Barrie, were charged in April with pandering obscenity and displaying nude photos of children. The photographs were from the exhibit ''Robert Mapplethorpe: The Perfect Moment.''

The seven-week exhibition of photographs by Mapplethorpe, who died of AIDS in March 1989, attracted a record crowd of more than 80,000 people to the gallery last spring.

About 150 gay-rights and anti-censorship demonstrators protested the trial outside the Hamilton County Courthouse from mid-morning through the noon hour Monday. They sometimes disrupted traffic, but there were no arrests.

The charges are both misdemeanors. If convicted, Barrie, 43, faces a possible fine of $1,000 and six months in jail on each count. The gallery could be fined $5,000 on each count.

A panel of eight jurors and two alternates will be chosen to hear the trial in Hamilton County Municipal Court. Jury selection was expected to continue through Tuesday, with testimony lasting into next week.

A pool of 50 prospective jurors was assembled Monday, but attorneys got less than halfway through questioning the first group of eight.

''Would you avoid a homosexual art display?'' the gallery's attorney, Marc Mezibov, asked one prospective juror.

''I wouldn't put out money to see homosexual art,'' the man responded.

Mezibov also told prospective jurors that testimony will deal with Mapplethorpe's homosexuality.

Prosecutor Frank Prouty asked prospective jurors whether they had seen Playboy, Penthouse or Hustler magazines and whether they had taken art classes or attended an arts fund-raiser.

Judge David Albanese asked all 50 prospective jurors if they had any personal contact with the art community. One person said she was a member of the Contemporary Arts Center, and three said they had seen the exhibit.

Protesters outside denounced the trial as homophobic intimidation.

They chanted, ''Art on trial,'' and carried signs that said, ''Stop gay bashing'' and ''Art today, your bedroom tomorrow.''

Demonstrators, accompanied by mounted police, walked 10 blocks through downtown, twice passing the gallery. Some people lay in the street, briefly halting traffic.

Catherine Adams, a lawyer for Gay-Lesbian March Activists, said she told city and county authorities last week that some members of the group had AIDS. About 50 officers, some of them wearing rubber gloves, set up barricades and patrolled the area.

A grand jury indicted Barrie and the gallery, concluding that seven of the 175 Mapplethorpe photos violated community standards. One photo shows a man urinating into another man's mouth. Others show oral sex and anal penetration with objects.

Officials of the American Civil Liberties Union and the Association of Art Museum Directors have said this is the first case they know of an obscenity prosecution of an art museum.

Albanese denied a defense motion to declare a mistrial based on pretrial news reports, particularly use of phrases such as ''child pornography.''

He also denied a motion to limit potential jurors to Cincinnati residents. Because of the structure of the Hamilton County Municipal Court, the jury pool is drawn from residents of Cincinnati and its suburbs.

The judge denied a motion to allow individual questioning of potential jurors and denied a defense request to increase the number of pre-emptory challenges.