The Japanese influence has long been felt in American business. Now the nation's first major institution building devoted to Japanese art brings a new cultural influence as well.

The Los Angeles County Museum's $12 million Japanese Pavilion is the product of some unexpected allies.An Oklahoma couple, who have perhaps the greatest collection of Edo period Japanese scrolls and screens outside the Japanese Imperial collection, hired a Texas architect to design the building. Japanese businessmen staged a massive drive on both sides of the Pacific to raise funds for the building.

The museum recently gave United Press International a preview of the 32,100-square-foot building, scheduled for a Sept. 25 gala opening. The pavilion combines exhibition spaces - replete with waterfalls and calm pools - a library and study area and office space.

The pavilion was constructed to house the Shin'enkan collection of 300 screen and scroll paintings, and a recent gift of several hundred netsuke, decorative figurines and ornamental buttons, from collectors Raymond and Frances Bushell of San Francisco.

The Shin'enkan collection, a promised gift to the museum by Mr. and Mrs. Joe Price of Bartlesville, Okla., who also donated $5 million toward the building construction, is considered one of the major Edo period (1615-1868) collections in the world.

Sebastian Izzard, head of Christie's Japanese Department, said, "The collection and the pavilion will serve as catalysts for future study and appreciation of Japanese art, which has grown in recent years.

"The British Museum is building a Japanese wing and the Victoria and Albert Museum in London already has the Toshiba Gallery. But the Los Angeles building is a major development on the American scene," Izzard said.

The Metropolitan Museum of Art opened 11,000 square feet of gallery space devoted to Japanese art in April 1987, and the Freer Museum of Art in Washington, D.C., is a major repository of Japanese art. The Los Angeles pavilion is, however, the first major American or European institution building devoted entirely to its study and exhibition.

The pavilion itself, a biomorphic or nonproportional multileveled structure of reinforced concrete and steel, has drawn mixed reactions from the art and architecture community.

"Frank Lloyd Wright would be happy with this one," said art dealer Christopher Ford of the Pence Gallery. "He once called Los Angeles architecture the boxes Disneyland came in. This building looks like the first museum with a flume ride," Ford said, referring to the gently sloping ramps on two sides of the building.

Albuquerque, N.M., architect Bart Prince developed and executed the pavilion's design after the original architect, Bruce Goff of Oklahoma City, died in 1982. He laughs at various descriptions of the building, including one by a fellow architect calling it "Fred Flintstone-Japanese."

"This building is the opposite of European modernism or postmodernism. It is designed from a specific function and does result in some unusual forms," Prince said. "It is large-scale sculpture that grows from the inside out. It respects the art from within."

The unusual design stems from the architects' desires to optimize natural light. The exterior walls are made of Kalwall, a translucent material that permits light to enter a room in much the same way a Shoji screen does - varying according to time of day, weather and season.

The entire structural support comes from three main columns, connected by bone-shaped beams and cables.

"It wasn't some wild notion of a museum. The shapes are not arbitrary. They come about as a result of the function," Prince said.

A continuous curving interior ramp connects six viewing platforms. The harsh California sun is softly filtered by the Kalwall, illuminating the artwork hung in traditional mahogany alcoves, known as tokonoma.

The building is connected by a walkway to the Los Angeles County Museum of Art's four other buildings and is surrounded by a lush Japanese garden.

The pavilion's east wing forms a permanent home for the Shin'enkan collection, portions of which will be changed several times a year.

The west wing contains areas for the display of sculpture, ceramics and netsuke, and for special exhibitions. There is also a library and study area featuring a traditional Japanese kotatsu, or sunken scholar's table.

According to fund-raisers, museum personnel and the architects involved, finding a home for the Shin'enkan collection was no easy matter.

"Bart Prince and Joe Price looked all over the world before deciding where to build the pavilion," said Toshio Nagamura, the California First Bank board chairman who led a $4 million fund-raising drive in Japan and the United States for the pavilion.

"The decision was finally reached to have the institution in Los Angeles," Nagamura said. "This is the most developing area of Japanese business in the United States. It is at the top of industry and economy. Now, there is Japanese culture also."