The Little League world champions from Taiwan toured Washington yesterday, from the Monument up to the Capitol to an old-fashioned barbecue in Arlington, but when it came time to play ball they respectfully bowed out.

After nearly 24 hours of frantic diplomatic maneuvering, their Arlington hosts determined that Little League officials in Williamsport, Pa., would never let a scheduled exhibition game go on between the Arlington Optimist all-star team and the Taiwanese.

So the finest team of 11- and 12-year-old baseball players in the world filed into the stands at Barcroft Park, along with about 500 fans who had come to see them play, and together they watched an Optimists' intrasquad scrimmage.

The makeshift arrangement came after top Little League officials steadfastly refused to budge on an issue of Little League rules.

The 14 Taiwanese boys had won the World Series in Williamsport Saturday, beating the U.S. South team from Tampa, Fla., 4-2. They came here Sunday, and until that evening the Arlingtonians thought the visit would culminate in an exhibition game last night.

It was the plan, anyway, until Little League President Creighton Hale got word.

In an inexplicable foul-up, Arlington League officials thought the Taiwanese had agreed to the exhibition game. They put out the word in newspapers and on radio, inviting the public to the free game at 7:30 p.m.

But when they arrived here the Taiwanese officials said they had never agreed to any such game, which would have violated Little League rules and jeopardized their Little League charter.

"We never talked about a game to anyone," said George Liu, an official in Taiwan's Washington-based Coordination Council for North American Affairs, which replaced the embassy when Taiwan-U.S. relations fizzled.

The Optimist Club sponsors several teams in the Arlington League, a baseball organization for 11- and 12-year-olds that is not affiliated with the Little League.

"A member of the Optimist Club talked to me about a picnic and swimming with some American boys and I said fine. But there was nothing about a game," said Liu.

The misunderstanding came to a head Sunday afternoon when Optimist leaders presented an itinerary of planned events.

S.T. Hsu, one of Liu's colleagues, said the itinerary showed a pool party, visits to the tourist attractions yesterday, followed by a picnic at Barcroft Park. Then, Hsu said, it read, "6:30, program begins. 7:30, going into the field."

Going into the field, it developed, meant playing an exhibition game. A Taiwanese veteran in such matters advised team leaders that such a game would pose problems. (Taiwan teams have won 10 of the last 12 Little League World Series and certain Taiwanese have grown expert in the intricacies of Little League policy.)

The visitors said they would need written permission from the Little League to play. Bob Bonaccorso, coach of the Arlington team, contacted Hale Sunday evening. The answer was no.

"Our regulations do not permit Little League teams to engage in special games," Hale said yesterday. "That's been the regulation since the start of Little League. We don't believe children this age should be barnstorming around the world.

"Arlington is not even a Little League," he added. "We don't approve of Little League teams playing out of the League structure."

He said if the Taiwanese did play, their Little League charter would "definitely be revoked."

Hale cited Regulation 9 of the Little League Code, which specifies, "Unless expressly authorized . . . games played for any purpose other than to establish a League champion or as part of the international tournament are prohibited."

So the Barcroft game was out, leaving Bonaccorso and his colleagues with a prospect of a large crowd and no show.

He looked for a compromise. While youngsters from the two teams visited Washington's favorite attractions, he met with the Taiwanese team leader, Ming Hue-chen, with Hsu and Liu and with his own allies at the Optimist Club, looking for a way out.

"I think they're praying for rain," said Hsu. "It's really very sad."

The harder Bonaccorso tried, the more firmly Hale denied. "This morning he was saying if we played they would take away our charter," said Hsu. "This afternoon he said they will take away the championship."

That would never do for the Taiwanese, to whom the Little League world championship is the biggest sporting achievement of the year. Sunny Young, a television commentator who accompanied the team, said about 10 million Taiwanese watched the final game when it was broadcast live at 2 a.m. Sunday, Taiwan time.

The Arlington organizers were crushed. "They (Little League officials) told us they wouldn't even let the Taiwanese kids play soccer," said Bonaccorso. His final plan was for an intrasquad game between the Arlington youngsters "in honor" of the visitors, with handshakes all around.

But Little League officials advised the Taiwanese not to appear in their uniforms on the same field with the Arlingtonians, Hsu said, "and uniforms are the only clothes they have."

While the depressing debacle wound its way to completion the youngsters had a good old time. The Taiwanese, wearing pin-bedecked caps and blue warm-up uniforms, ate hamburgers at the Air and Space Museum cafeteria, wandered around the Capitol statuary and joshed with and poked at their American counterparts.

They commented on their victories. Ace pitcher Chang Ming-pin, asked how the U.S. South team managed a two-run homer in the final game, said, "The home run of the other team was like a blind cat finding a dead mouse. Pure accident."

It was tougher for the Americans, particularly in the morning when they learned the game was scotched.

"When we were sitting at the Monument, in the sad, sad chairs with the tears streaming down our eyes, it's true, man, I was crying," said Adam Marrocco, half-seriously.

"We told all our friends we were going to play the world champions and they said, 'Ah, bull.' Now we have to go back and face them."

Marrocco said he figured Williamsport vetoed the game because, "If we beat 'em, like we would, they figured we'd go around saying, 'We're the world champs.' I think they are a little selfish."