Arthur A. Fletcher, the Republican nominee for mayor, sharply attacked his Democratic opponent yesterday, telling a group of ministers that Marion Barry has a short history of "responsible" behavior and is being supported by those who want to "buy the mayor's office" in next month's general election.

"This is green powere versus soul power. The people who are supporting Marion Barry have decided that their green power can buy the mayor's office," said Fletcher, whose campaign has rised less than one-tenth as much money as Barry's. "I'm not blaming Marion for that, I'm blaming the people behind him."

"I did't just learn recently that it pays to be responsible," Fletcher told about two-dozen ministers who endorsed his candidacy yesterday at Mt. Sinai Baptist Church, 1615 3rd St. NW. "I will put my performance for responsibility up against my opponent decade by decade and we'll see what we did with our minds, out time and our energy and what the bottom line has been."

"I'm not rich in money, but I am rich in skills," he said, concluding his remarks by saying, "You can trust me gentlemen: I can't be bought."

Florence Tate, Barry's campaign press secretary, declined comment on Fletcher's remarks, which were the latest development in a continuing battle between the two major candidates in the Nov. 7 general election for support within the city's influentiual black church community.

Barry is to announce today a list of ministers who support his campaign.

At yesterday's press conference, more than a dozen churchmen came to the pulpit to announce their support for Fletcher, including the Rev. Andrew J. Allen, pastor of First Baptist Church of Deanwood, and the Rev. Raymond of Robinson, pastor of Israel Baptist Church, who formally announced Fletcher's endorsement by the Committee of 100 Ministers.

Allen said he exected many more ministers, as many as 100 or more, to join the effort and contribute volunteers, workers and votes to Fletcher's organization.

The Rev. John J. Koger, pastor of New Bethaney Baptist Church, 1300 10th St. NW, pulled a $100 bill from his wallet and contributed it to the Fletcher campaign.

"Take this. That's good money," he said, stretching his arm toward Fletcher. "And there's some more where that came from."

In the September Democratic primary, most of the city's ministers supported either Mayor Walter E. Washington or City Council Chairman Sterling Tucker, both of whom were defeated by Barry in a close 3-way race.

Since the primary, Fletcher and Barry have been seeking support of the ministers, whose church members are considered by many to be a significant part of the city's regularly voting electorate.

Barry, a former black activist, long has been distrusted by many city churchmen because the "street dudes, - hard core unemployed youthss - he worked with in the late 1960s often were considered "hoodlums."

Opposition to Barry by the clergymen has heightened in the time that Barry has been on the council since 1974 because of his support for inclusion of gay rights in the city's human rights ordinance, lessening of penalties for marijuana use and his association with the establishment of a citizens study commission that has recommended legalized gambling in the District of Columbia.

Gambling, gay rights and marijuana legalization were the principal objections to his candidacy voiced yesterday by ministers.

Fletcher stands for "the principles which this Bible sets forth as a ground rule for morality," said the Rev. David Durham, pastor of Mt. Sinai Baptist. "I do not want my children exposed to a city where they endure this permissiveness."

Several of the ministers urged blacks, who make up the majority of the city's population, to abondon the tradition of voting primarily Democratic, as blacks have done since Franklin D. Roosevelt's "New Deal" administration of 1933-1945. Nearly 80 percent of the registered voters in Washington are Democrats.

"I think it is time," said the Rev. John D. Bussey of Bethesda Baptist Church, "that was a people stop being predictable politically."

Robinson, president of the interden ominational Committee of 100, said about 20 members of the group had voted Oct. 3 to support Fletcher. Robinson said yesterday that he could no assure that all 1 ministers - or ever the majority of the group - would abide by the vote, however.

The Rev. Edgar L. Williams, pastor of Second New St. Paul Baptist Church, and chairman of the board on another minister's group, the John F Kennedy League for Universal Justice and Goodwill, also endorsed Fletcher. But Williams said his group, which supported Democrat John Ray in the primary, has yet to make a formal endorsement. Ray has endorsed and is now working in Barry's campaign.

Among others at yesterday's press conference were the Rev. H. Wesley Wiley, Covenant Baptist Church; the Rev. A.L. Colston, Glendale Baptist Church, the Rev. Jerry A. Moore Jr. Nineteenth St. Baptist Church and a Republican City Council member and the Rev. Imagene Stewart, of the Church of What's Happening Now.