President Ford has decided to pardon Iva Toguri D'Aquino, known to millions of World War II servicemen as "Tokyo Rose," administration officials said yesterday.

D'Aquino, actually one of at least a dozen women who broadcast to American troops over Japanese radio, was convicted of treason in 1949 and served 6 1/2 years in prison.

Her trial took place in an anti-Japanese atmosphere in San Francisco, and only the prosecution was allowed to subpoena Japanese witnesses. The foreman of the jury, John Mann of Berkeley, told reporters last year that the jury had convicted her only because of pressure from the judge and said he wished he "had a little more guts to stick with my vote for acquital."

The American-born D'Aquino, now a 60-year-old clerk in an Oriental gift shop in Chicago, married a Portuguese citizen in Japan during World War II. The two have long been separated, because he was not allowed to travel to the United States and she was not allowed to visit abroad.

After World War II D'Aquino was held for two years without trial. She consistently refused to renounce her American citizenship, and she was therefore the only one of the many "Tokyo Roses" who was ever brought to trial.

In recent years testimony by those who knew her in Japan during the war produced information that D'Aquino had smuggled food and clothing to the three Allied officer prisoners of war for whom she worked on Japanese radio and who produced the program. All of the officers were promoted after the war.

D'Aquino has been portrayed by her defenders as a victim of wartime hysteria. Not even the Japanese-American Citizens League, then helping the Japanese-Americans who had been detained in camps during the war, would come to her defense at the time of trial.

D'Aquino, who called herself "Orphan Ann" not "Tokyo Rose" on the air, always insisted that she was innocent and that her broadcasts actually concealed messages to Allies and prisoners of war. She was tried on eight counts but convicted on only one, of stating in a broadcast:

"Orphans of the Pacific, you are really orphans now. How will you get home now that your ships are sunk?"

D'Aquino's attorneys argued that this statement was not intended seriously and could not possibly have been taken that way, since the Allies had just won a major sea victory.

The officials who disclosed the pardon yesterday said also they did not expect that President Ford would pardon any persons who were convicted in the Watergate case.