Chinatown bursts cultural seams. San Francisco's Chinatown is feeling an international crunch. Hong Kong developers are competing with Vietnamese immigrants and Chinese-speaking newcomers for space.

San Francisco's Chinatown, for decades a symbol of Chinese tradition in the United States, is in the throes of an identity crisis. New immigrants, flashy storefronts, and Hong Kong investors threaten the neighborhood's traditional character, say many residents. ``This used to be a closed community, now it's an international community and we have to pay the price,'' says Dr. Rolland Lowe, past chairman of Chinese Hospital and head of the Chinese Cultural Foundation.

Part of the price is less housing and fewer jobs available for residents, including the newcomers. The old story of whole families living in shabby hotel rooms or boarding houses persists. Low-cost housing is one of the settlement's long-neglected needs. There has been talk of establishing a Southeast Asian refugee-resettlement center but nothing concrete has emerged.

Dr. Lowe estimates that 12,000 to 13,000 Chinese-speaking immigrants land yearly in San Francisco, though they do not necessarily stay in Chinatown. Among them are Chinese mainlanders, Hong Kong residents, Macanese, Vietnamese (of whom 70 percent speak Chinese), and a few Taiwanese. Those who settle in Chinatown are mostly unskilled workers.

Chinatown's population has been estimated at 30,000, up from 15,000 in 1980. Space is short and residents are pushing its boundaries into the formerly Italian area of North Beach and the financial district.

There are new faces in town, too. From 3,000 to 4,000 Vietnamese live in Chinatown, says John Fang, publisher of the US newspaper Asian Week. Their arrival in large numbers started about three to four years ago, and now they own some 50 stores. Mr. Fang hails them as ``the new blood of Chinatown.'' It is now their turn to struggle for survival just as the generations of Chinese immigrants before them.

Several Chinatown leaders feel that promoting tourism will create service jobs for the unskilled in restaurants, hotels, and shops. Of course, such development may also endanger the settlement's ``character'' that it wants to preserve. The Chinatown business community does not have a vision or a plan of how it wants to see Chinatown develop, Lowe complains. ``We should encourage appropriate businesses.''

Ironically, the territory's Hong Kong investors are also causing dislocations in Chinatown, where four out of five residents have come from or through Hong Kong.

How many investors or how much money comes from Hong Kong is nearly impossible to quantify because there are so many companies and individuals concerned and much of the investment is indirect.

Residents are concerned about the Hong Kong investors who pay high prices for property. If a building generates $500,000 in rental income, for instance, a foreign investor may buy it for $1 million and up the rent. This inspires long-time local property owners to raise their rents for residential and commercial space - so both residents and small business owners suffer from rocketing rents.

Lowe fears a backlash against Hong Kong investors. ``The Chinese American wants a good image,'' he says.

Former Hong Kong resident, James Ho, deputy mayor for business and economic development, sees it differently. He believes the Hong Kong investor brings new life to Chinatown which for decades had been dominated by old family associations.

After leaving Chinatown, many Chinese move to other parts of the city, Oakland, San Jose, or San Francisco's Richmond district - the ``new Chinatown.''

The Chinese moved there because the houses are solidly built and large enough for their families, says Fang. Also, he points out, the San Francisco Municipal Railway's No. 1 bus goes straight from Chinatown to Richmond, an important link.

``Second and third generation Chinese are spreading to the suburbs and that's fine. Chinatown should be a place for immigrants to get assimilated and move on,'' Fang says.

Mr. Ho, past president of the Chinese Chamber of Commerce, would like to see Chinatown old-timers and newcomers alike broaden their outlook to embrace all of San Francisco, rather than just the concerns of their tiny community.

On its narrow streets, buildings stand cheek by jowl, ornamented by traditional peaked and tiled roofs. Now 130 years old, Chinatown is situated in the heart of San Francisco, surrounded by Nob Hill, Union Square, and North Beach.

On the surface, much of the old order survives. Many of its old fa,cades reveal engravings of the year they were built and their earlier uses. On Clay Street near Grant Avenue, for instance, on a building whose ground floor is occupied by a tax accountant and a notary, appears the faint legend, ``Quong Fook Tong Benevolent Association,'' and the date: ``AD 1912.'' This structure is one of the area's youngsters.

Souvenir and jewelry shops are the staple of Grant Avenue, the main tourist thoroughfare. Like its competitors in the neighborhood, the so-called Chinese Trade Center sells kites, T-shirts, cheap jade, and basketry. An elderly musician plays the erhu in front of the Empress of China restaurant and expects a gratuity for a photo. The Bank of Canton sits next to a building advertising acupuncture treatment.

Parallel to Grant Avenue, Stockton Street is the residents' shopping area with its grocers, butchers, ginseng and herb shops, tax consultants and notaries, pastry shops, and the fairly recent appearance of Vietnamese restaurants.

``Sometimes I cannot tell the difference between San Francisco and Hong Kong. This is a strong Cantonese town, street signs in Chinese and English. Nowhere else do you see that,'' Fang effuses.

But behind the aging fa,cade, the signs of change increase. Six recent discount camera shops on Grant Avenue disturb the cohesion of chinoiserie. Since the street is only about eight blocks long, their presence is jarring. Residents resent the fact that they are owned by ``foreigners,'' or non-Chinese.

Some residents want new zoning regulations to discourage such enterprises. City Supervisor Tom Hsieh has been mustering support for such legislation.

Philip Choy, architect with Hardine & Choy Associates and a well-known preservationist, fulminates over these intrusions. ``It's not the camera shops I object to, but the manner of merchandising and advertising. If we are careless about the historic fabric of Chinatown, it could become a honky-tonk area.''

Mr. Choy, who leads a walking tour of the area, says most of the buildings, with restoration, could be coaxed to yield up their historic riches. ``Chinatown has been a slum area, but it doesn't have to be. It can be dignified.''