French Foreign Minister Claude Cheysson today dismissed as intended for American home consumption yesterday's State Department declaration that the naming of Communists to the French Cabinet would change the "tone and content" of Franco-Amrican relations.

In a radio interview, Cheysson said the best possible proof of the purpose of the State Department communique is that "here they had the best possible spokesman on earth -- the vice president of the United States -- in Paris. He could say anything he wanted to. But, no, they published it over there . . . over there while Bush was here, which does prove that it is indeed intended for their own public opinion. They need to be reassured."

Neither Bush nor U.S. Ambassador Arthur Hartman would comment on reports that they were surprised and annoyed at the State Department statement. Bush's own statement here yesterday was considerably milder in tone than the one issued in Washington.

Cheysson was clearly in a cheerful mood in appearances today, and his and other official statements indicated that the new French administration intended to give the lightest possible interpretation to the U.S. utterings of disapproval.

A French presidential spokeswoman said that Mitterrand had taken the State Department statement "philosophically" and "with calm." She noted that visiting Canadian Prime Minister Piere Elliot Trudeau, who saw Mitterrand today, had been "more serene" even than Bush.

Upon emerging from the Elysee Palace, Trudeau said, "It will not change in any respect our relations with the French. . . . It is a political gesture not completely different from the one thing that I attempted myself when after my election as a majority [in Parliament] I invited some Socialists into my government."

Canadian briefers said that Trudeau had not raised the question with Mitterrand and that it was the French president who has insisted on laying out his reasoning for the appointments. The briefers said that the two leaders had joked and laughed together about the American expression of concern.

Foreign Minister Cheysson said that the Americans were reacting as they were because "maybe they though this was contagious. . . .From the United States, they have a hard time seeing the difference between France and Italy, France and Spain, etc. I think the communique reflects that error in evaluation."

He noted that the French political and institutional situation is unique because the Socialists are now so much stronger than the Communists and because the French president "has full power at any moment to name a minister or to dismiss a minister."

Asked about a U.S. television report that President Reagan had received assurances from Mitterrnd that the Communists would be kept away from defense secrets, Cheysson dismissed it as "James Bond talk," but he said he was prepared to explain to anyone, including the Americans "or the Paraguayans" that government matters are dealt with only in small, restricted meetings involved the ministers concerned. "The transportation minister will not deal with defense," said Cheysson, referring to Transportation Minister Charles Fiterman, the most senior of the four Communist ministers in the 44-member Cabinet.

Bush resisted a barrage of attempts by reporters at an airport departure press conference this morning to get him to explain the State Department declaration. He referred reporters, however, to the warm, friendly words that surrounded the cool ones in the text and repeated several times that interpretations of the Washington text as hostile to the Mitterrand government wee inaccurate.

"In my view, the historic position of our country has been expressed, and that's really all I have to say on that subject," he said.

Bush went out of his way this morning to stress how friendly his talks with Mitterrand and other French leaders had been during his 24-hour stay here. He said he had told Mitterrand, "We want very much for him to come. . . . I know from the standpoint of the United States, the [French] president will be given a very warm reception by President Reagan.

"I feel very comfortable about the relationship between the new government and the United States. That is not to say there are not some differences. But the beautiful thing about it is I was immediately given a feeling that without prejudice we could discuss these differences just as we discussed a wide array of common agreement . . . and that's the important point."