As the political junkies of the Hollywood Hills stumbled home today in the glow of trans-Pacific good will, no one was sure if Michael Woo's big victory had anything to do with his being Chinese.

Certainly the candidate's wealthy father and Chinatown friends had helped provide the money to launch his bid for a Los Angeles City Council seat. Just as certainly his unsuccessful campaign four years ago had been soured by opposition leaflets labeling him and his backers "outsiders."

On Tuesday, contending for a district that is no more than 5 percent ethnic Asian, the methodical, 33-year-old Woo became the first Asian American elected to the city council of a metropolis with more than 1 million people. He added his name to a growing list of young ethnic Asians assuming power in the western United States.

Woo also restored the faith of many political operatives that, despite one recent disappointment, the city's future is in the hands of those who would make room for immigrants pouring in from Asia and Latin America. But his victory also left doubt that the success of young ethnic Asians like Woo reflects their ability to attract voters of similar heritage.

In the last few years, the Latino portion of Los Angeles's 3 million people has risen to 27 percent and the Asian portion to 7 percent; until now its City Council consisted of 12 whites and three blacks. A ballot measure to give Latinos and Asians a boost by adding two seats to the council lost in April.

Several experts noted today that Woo's victory is likely to be followed closely by the addition of a Hispanic council member. Council member Arthur K. Snyder has announced that he will retire soon from his district, which has a large Latino population.

Ruth Santana, a staff associate engaged in setting up an Asian caucus at the National League of Cities, said her still-incomplete survey has turned up seven mayors, one council president and 27 council members of Asian ancestry. These include Frank Wing of San Antonio, Dolores Sibonga of Seattle and Frank H. Ogawa of Oakland.

Some of these officials have been elected in Hawaii or in some small Los Angeles suburbs where ethnic Asians form a large part of the electorate. But many others, including Woo, seem to have succeeded almost despite their constituencies.

California Secretary of State March Fong Eu, Rep. Norman Y. Mineta of San Jose, Rep. Robert T. Matsui of Sacramento and now Woo have shown how Asian Americans win elections where most of the voters are white. They create a web of loyal supporters, work hard on constituent services and develop a polite persistence that may not win headlines but seems to inspire confidence.

Since his defeat by City Council member Peggy Stevenson, 62, in 1981, Woo has conducted an almost continual, if unannounced, campaign in the 13th District along the city's northeast corner. As a senior consultant to state Sen. David Roberti, whose district conveniently overlapped District 13, Woo appeared regularly at meetings of homosexuals, Armenians, Hispanics, young professionals and dozens of other groups.

Woo has been active in the Democratic Party's Asian-Pacific Caucus and decries national party Chairman Paul G. Kirk Jr.'s decision to withdraw official status for it and other minority caucuses. But Woo and his advisers have concluded that his victory had far less to do with his ethnic ties than his links to his fellow young American professionals.

"It was experience and education," said caucus treasurer Michael Eng, 38, a local immigration attorney, noting that Woo has a master's degree in city planning. Woo's new ties with the West Los Angeles political organization of Reps. Henry A. Waxman and Howard L. Berman also gave him a crucial edge.

In the primary, Stevenson had beaten him 42 to 35 percent, forcing a runoff for lack of a majority. After shrugging off a charge involving illegal contributions from a fireworks manufacturer, Woo revealed a series of endorsements, unusually prominent and potent for a city council race, that helped propel him to his 58-to-42 percent victory.

Two incumbent council members supported him. Berman, Eu and District Attorney Ira Reiner added their endorsements, and the campaign's last days climaxed with the announced support of Sen. Alan Cranston (D-Calif.), up for reelection next year in a rapidly changing state.