Arena Stage wins the hearts - and pocketbooks - of Washington

''We prowled through the community in search of loose cash,'' said publisher Donald E. Graham with a disarming grin, ''and we raised two and a quarter million dollars.''

Mr. Graham, publisher of the Washington Post, stood in a spotlight at the Arena Stage here talking about the down payment pledge on one of the most formidable endowment campaigns ever to take a bow in a US resident theater company. As head of the Arena Stage's new endowment campaign, Mr. Graham and his fellow chairmen are raising the curtain on a $6 million campaign goal for the nonprofit theater company.

Under its producing director, Zelda Fichandler, Arena Stage has become not just a Washington theatrical landmark with 18,000 subscribers but a nationally recognized source of innovative productions. Among the Broadway productions which originated at Arena Stage are ''K 2,'' ''The Great White Hope,'' ''Indians ,'' and ''A History of the American Film.'' In 1976 Zelda Fichandler and Arena Stage won a special Tony Award, the first given to a company outside New York.

Ms. Fichandler, dressed in cream from her silk suit and pearls to her pumps, spoke of the paradoxical history of Arena since she and her husband, Thomas, founded it: ''The longest journey (was) from 1949, when Arena started with a $1. 98 cardboard file box. Now, 35 years later, when we're launching a $35 million endowment campaign, we're still childlike in our curiosity and we're divinely reckless and guileless and trusting,'' the vision that began it all.

She quoted then from Camus: ''If the world were clear, art would not exist. Art helps to pierce the opacity of the world.'' While survival rather than artistic quality may be the name of the game in theater today, she suggested, ''Creativity can't always be cost effective.''

Among several others seated center stage in front of a white-pillared-blue-sky-set at Arena's Kreeger Theater were multimillionaire banker and former Washington Star publisher Joe L. Allbritton, National Endowment for the Arts chairman Frank Hodsoll, and producer-director-actor John Houseman, who has his own nonprofit theater troupe, The Acting Company.

Mr. Houseman, dressed in a serious gray suit with a vest and bow tie, surveyed the audience with the implacable gaze that unnerved Harvard law students in ''The Paper Chase.''

''We appear to be talking about sordid money,'' he began, ''but I'm more concerned about talking about art for a minute.''

He said that in the late 1940s and early 1950s ''if anyone had predicted that theater was finished and might survive as a museum . . . he would have done so with considerable reason and justification.''

Then what Houseman calls ''the miraculous phenomenon'' of regional theaters began springing up all over the nation, daring to do new plays and reviving the institution of the theater across the country. One of the best of these and one of the earliest was Arena Stage, Houseman said, and there are now as he pointed out, more than 200 of them.

Throughout his speech and the others a small baby in a scarlet pinafore in the audience gooed and gurgled appreciatively.

The campaign began with a $750,000 challenge grant from the National Endowment for the Arts, with the additional $1.5 million initial pledge coming from corporations, individual ''angels'' and foundations. Arena's budget this year is $5.8 million, of which 73 percent, a high percentage for a nonprofit organization like this, is paid by box office and ''related'' earnings.

After the announcement of the campaign kickoff to an audience full of Arena backers and press, a small celebration party was held in Arena's Vat Room. There in the middle of tables bearing strawberries, Brie cheese, and grapes, an announcement was made and cheered: One local couple had just come up with some ''loose cash'' for the campaign: a $50,000 Arena endowment pledge.