At the south end of Chinatown, residents are preparing to wave Chinese flags and sing Chinese songs this weekend, celebrating the Beijing Olympics. But the events’ organizers don’t expect anyone from the north end to show up. Rather than bringing Manhattan’s Chinese-Americans together, the Summer Games are reinforcing divisions within the community.

On one side stand the men who lead the old immigrant organizations of north Chinatown and are distancing themselves from the games. On the other side are men who represent a booming group of newer immigrants from the Fujian region of mainland China, who are publicly celebrating the games, and who are tipping the scales of power in the neighborhood.

Tomorrow, hundreds of Fujianese are scheduled to rally in Foley Square, and on Sunday they are scheduled to march in a parade from the middle of the Brooklyn Bridge to the heart of the Fujianese community on East Broadway. Those gatherings have sparked harsh words between leaders on both sides of Chinatown.

The president of a 125-year-old, Taiwan-allied community organization, Justin Yu, said there was “nothing happening” to celebrate the Olympics among New York’s Chinese-Americans.

“They don’t want to be a part of it,” the vice president of a Fujianese group who is organizing the parade, Jimmy Cheng, said in response to Mr. Yu’s comment. “For the Olympics, he should be coming to me for celebrations. He should get together with the Fujianese.”

But international political allegiances are getting in the way of such a joint event.

Mr. Yu’s organization, the Chinese Consolidated Benevolent Association — often referred to as the City Hall of Chinatown, or by its abbreviation, CCBA — has maintained a pro-Taiwan, anti-Communist stance since Mao Zedong’s takeover in 1949, according to its official literature.

“The mainland government, they’re Communists, and we don’t like that,” a 74-year-old business consultant who works for the association, Chan Ming Chien, said. “The new immigrants came from China in a happier time, so they like it more than I do.”

“We need a modern China, and it should respect individual rights,” Mr. Yu said.

The CCBA has held no Olympic celebrations, and does not plan to hold any, according to Mr. Yu. The same goes for other large cultural organizations such as the Chinatown Partnership and the Chinese-American Planning Council.

In stark contrast, the Fujianese organizers of this weekend’s events are openly pro-Beijing.

“The CCBA are old. They’re part of Taiwan. We are from Red China,” Mr. Cheng said. His organization, the United Fujianese American Association, escorts Chinese businessmen through New York every month, and its logo consists of intertwined Chinese Communist and American flags.

“Most of our people are born in the People’s Republic of China, and that’s why they’re so close to it,” another Fujianese group president, Kenneth Cheng, said. “We are celebrating because we want the world to know that China is important.”

“People who protest about human rights in China, they don’t get it,” Jimmy Cheng said. “China needs to do what it needs to do.”

Both Kenneth Cheng and Jimmy Cheng — who are not related — said they do not expect to see non-Fujianese at the rally or the parade.

In demographics, as well as political influence, the Fujianese community has grown rapidly in recent years.

They began to come over in large numbers during the 1980s, after border restrictions with China were relaxed, according to a professor of sociology at Occidental College who specializes in Chinatowns, Jan Lin.

Meanwhile, the waves of immigrants from Taiwan and Hong Kong who filled the ranks of older Chinatown organizations have dried up in comparison. In 2006, 61,563 immigrants from China, excluding Taiwan and Hong Kong, immigrated to Manhattan, according to the Department of City Planning. Mr. Yu said the majority of those immigrants are Fujianese, and Jimmy Cheng concurred.

In that same period, only 9,329 immigrants came from Hong Kong and Taiwan.

For years, the Fujianese and the Cantonese-speaking “historical core” of Chinatown almost never mixed, according to the executive director of the Chinatown Partnership, Wellington Chen. “Both sides have tried to claim that they represent the Chinatown community,” he said.

“The Fujianese were taking Cantonese jobs, and they were looking for the same benefits, so there was considerable acrimony,” a woman who did aid work for Fujianese immigrants between 1996 and 2002, Tracy Shupp, said.

Subsequently, relations have cooled, “but it’s still basically two different economies,” Mr. Chen added.

Jimmy Cheng emphasizes the division. “We did in 10 years what CCBA did in 120,” he said. “They don’t do nothing for us.”

He said his group has more than 1,000 members and registered 10,000 people to vote in 2004. He pointed proudly to two photographs, one of Senator Clinton meeting with his organization, and a similar one with Comptroller William Thompson Jr., who is a mayoral candidate. He said he raised $380,000 for Mrs. Clinton’s presidential campaign.

“Today’s immigrant is tomorrow’s citizen,” Mr. Cheng said. “That’s why all the politicians are starting to come here.”

Despite such rhetoric, leaders on both sides say they are looking forward to watching the Olympics.

“Generally speaking, there’s obviously a lot of pride in the fact that, for the first time in history, the torch has been passed to China, and that’s a unanimous comment that people are saying,” Wellington Chen said.

The more subdued response from the older organizations may be related to memories of what has happened to Asian-Americans in the past, according to a professor of Asian American studies at Hunter College who has written five books on Chinatown, Peter Kwong.

“When people think a country is undermining our industry, there’s a great deal of resentment for those immigrants,” Mr. Kwong said. “Chinatown people might have private banquets for the Olympics, but they’re not very likely to be overtly expressive about what they feel.”

One CCBA volunteer in his 20s, Karl Leung, said what matters is how long ago one’s family came to America. “If you look at a new immigrant, they might be rooting for China,” he said. “But I want to see LeBron James dunk on Yao Ming.”