Some of America's reigning comedy geniuses have proved to their satisfaction that the Chinese really do have a sense of humor.

The group, including Norman Lear, Carl Reiner, Larry Gelbart, Grant Tinker and Mary Tyler Moore - just returned here from a three-week tour of China - watched students at Shanghai's Futan University conduct English dialogues on a story about China's late, revered Premier Chou En-lai. The story told how Chou gave his parachute to a little girl who had been in tears during a hazardous airplane trip.

Up stood Reiner and Gelbart, whose most recent collaboration was the film "Oh, God," with George Burns in the title role. They launched into their won ad-lib dialogue. Rendered as if they were two students who hadn't quite gotten the lesson, they had Chou - almost a saint in China these days - in tears and the girls giving him her parachute.

"Why are you crying?" said Reiner in the guise of the child. "You've got the parachute."

The Chinese students broke up in a loud laughter, to the delight and relief of the American visitors.

It was the same in Peking when someone asked a high Chinese official a question about another bad deed of Peking's now-purged "Gang of Four." "I'd like to answer that for the minister," siad Reinter, jumping up. "It was terrible, just terrible." The Chinese in the room were convulsed.

"The Chinese, we found, have a great sense of humor, and not only that, a great sense of self-deprecation" said Lear, the creator of "All in the Family," who organized the tour with the help of the U.S.-China People's Friendship Association. It brought them into close contact with more Chinese television and movie writers, directors, actors and producers than perhaps any other American group to date, and left many of them with what they said was a warm feeling for the Chinese and a desire for continued progress in normalization of relations between Washington and Peking.

"My impressions are predominantly emotionally based," said Moore, who now returns to California to begin work on her new variety series." Obviously I don't know much about the politics and government . . . "I'm not naive to the point that I think nothing was staged, but what was not staged was the warmth of the people."

Tinker, Moore's husband and the head of the MTM studio that produced her acclaimed comedy series as well as "Rhoda," "The Bob Newhart Show," and many others, said, "The people we met have a better sense of humor, at least closer to what we American have, than the British, the French, the Russians and the Germans."

Little of it has shown up yet in Chinese movies and television. The group saw several films and some stage productions, including one dialogue that included almost vaudeville-style humor, but most of the works were laden with political messages. When asked for their comments on a particularly heavy-handed account of a street sweeper's life called "Thank You, Comrade," members of the group suggested that the Chinese "lighten it up a bit." The Chinese said they were working on it.

Except for affew Australian and American children on a school trip, nobody recognized Moore or the other American celebrities. But some of the Chinese actresses who escorted them were spotted by people in the street, an would sometimes stay behind in the tour bus to avoid mob scenes. "It was just like what happens to us back home sometimes," said Moore with a grin.

Some of the Chinese actors and cultural officials had read brief dossiers of the group members. "They'd been told that I was a very well-known actress in the United States," Moore said. "But one of the most difficult questions I had to answer was 'What did you do in your series?" Try to define what American situation comedy is, try to put it in their context . . . and you end up with egg on your face.

American films are not shown in Chinese movie theaters, but some top Chinese officials responsible for the arts said they occasionally screened Western movies to study technique. "A lot of their knowledge seemed to end in the 1930s," said one member of the group. "They wanted to find out what happened to stars of that era, like Hank Fonda."

"Some of the Chinese said they had seen a few more recent American films, such as "Westworld" with Richard Banjamin and Yul Brynner, and "Guess Who's Coming to Dinner," the last picture to star Spencer Tracy and Katherine Hepburn.

The Chinese poured over materials describing some of the latest in American film-making equipment, such as the "Steadicam," which Lear gave them. The Americans promised to send tapes and scripts of "All in the Family," "The Mary Tyler Moore Show," and anpthing else the Americans thought might interest them.

Lear selected the group after the Chinese expressed interest in meeting people from the American television and film industry. Besides Tinker and Moore Show," and anything else the Americans wives, the group included writer-producer David Rintels, writer-producer Robert Weiskopf, attorney Geoffrey Cowan and labor organizer Paul Schrade and their wives, plus producer Lee Rich and his wife.

"We went out with a deep and abiding respect and affection for the Chinese people," Lear said. "When we go back home we plan to ask our president to normalize relations with China and we also want to talk to our industry and get a cultural exchange going the other way," by inviting representatives of the Chinese film and television industry to the United States.

Lear siad he thinks the Chinese might someday find some use for an American-style situation series. "Archie Bunker is just like an old fascist who wants things to go on like they were before liberation," he said. "If someday they want me to come back for six months to help advise on something like that, I'm ready."