Howard Sackler, who won the 1969 Pulitzer Prize for drama for ''The Great White Hope'' was found dead yesterday morning in his studio in Ibiza, Spain, where he lived most of the year. He was 52 years old.

Mr. Sackler's lawyer in New York, Jay Harris, said an autopsy was being performed. Mr. Harris said Mr. Sackler died ''either Tuesday night or Wednesday morning.'' He added that there was ''no suspicion of a crime.''

''The Great White Hope'' was based on the career of Jack Johnson, who in 1908 became the first black heavyweight boxing champion. The drama, which opened on Broadway on Oct. 3, 1968, marked Mr. Sackler's Broadway debut. It also won the 1969 Tony Award for best play. Refused to Conform

James Earl Jones starred as Jack Jefferson, Mr. Sackler's fictional boxing champion who was resented by the society in which he had fought his way to the top and who was crushed because he did not care to conform .

Mr. Sackler said in an interview that he did not see his play as a story of racial conflict. ''What interested me was not the topicality but the combination of circumstances, the destiny of a man pitted against society,'' he said. ''It's a metaphor of struggle between man and the outside world.''

''Some people spoke of the play as if it were a cliche of white liberalism,'' he continued. ''But I kept to the line right through, of showing that it wasn't a case of blacks being good and whites being bad. I was appalled at first at the reaction.''

Mr. Sackler was the sole backer of ''The Great White Hope'' on Broadway. He financed the production with $225,000 that he made on the motion picture sale of his drama. He also wrote the screenplay for the film, in which Mr. Jones again played the role of Jack Jefferson. Had Same Director

''The Great White Hope'' was directed by Edwin Sherin, who staged Mr. Sackler's drama ''Goodbye Fidel'' on Broadway in 1980. Mr. Sherin also directed an acclaimed production of ''Semmelweiss'' for Mr. Sackler in 1977 at the Studio Arena Theater in Buffalo and a subsequent production at the Hartman Theater in Stamford, Conn. ''Semmelweiss'' was based on the life story of Ignaz Philipp Semmelweiss, the pioneering 19th-century physician.''Semmelweiss'' also had a controversial run at the Kennedy Center for the Performing Arts in Washington, where Mr. Sackler and Mr. Sherin clashed with Roger L. Stevens and Robert Whitehead, the producers, over casting and rewriting. As a result the play never reached Broadway, as had been planned.

At the time of his death, Mr. Sackler was finishing a new play called ''Klondike,'' a farce about the Gold Rush. Finishing New Play

Mr. Sackler also worked in the theater as a director. He staged productions in London, Dublin, Paris and in Los Angeles at the Mark Taper Forum. For many years he was also a director for a series of Caedmon recordings of poetry and plays.

For the movies, Mr. Sackler wrote ''Saint Jack'' with Paul Theroux for Peter Bogdanovich and was a co-author of ''Jaws II.'' Mr. Sackler was born Dec. 19, 1929, in Brooklyn and was graduated from Brooklyn College. He is survived by his wife, Lynn, and two children, Molly and Daniel.

Illustrations: photo of Howard Sackler