Voters in this old Confederate capital elected blacks to a majority of City Council seats Tuesday, ousting an entrenched power structure of white business and financial leaders who had governed Richmond, in one form or another,for nearly 30 years.

In a historic special election growing out of a six-year court challenge to the constitutionality of the way things were, a postal worker, an occupational therapist, and a student of urban planning were elected with two black incumbents to five of the nine seats on the Council.

"It's a whole new ball game," said Council member Henry L. Valentine II, a white stockbroker re-elected to serve with the new black majority. "I've been poring over these (elections) figures trying to think about our strategy . . . but I really don't know what we could do different."

Since 1948, when Richmond junked its old ward system for the city manager form of government, all nine Council members had been elected from the city at large.

White leaders had been able to counter the growing political power of the city's black population by rolling out an unusually high percentage of voters in the city's predominantly white areas.

But Tuesday, under a new court-ordered system that divided the city into nine single-member districts - four predominantly white, four predominantly black and one biracial "swing" district - the old politics no longer worked.

In Valentine's first district, 8,057 voters cast ballots but elected just one man - Valentine.

In Richmond's downtown area, 2,599 voted but they, too, elected one man - walter T. Kenney, the black postal worker.

Because of those voting patterns, repeated in varying degrees around the city, whites might have kept control of the Council had the old at-large system still been in effect.

The old system was overturned by the courts in the course of a challenge by the Rev. Curtis T. Holt Sr., a black civil fights activist with a sparse following among Richmond's black population.

Holt filed suit in U.S. District Court in 1971 to overturn Richmond's 13-month-old annexation of 23 square miles or land and 47,000 people - nearly all of them white - from suburban Chesterfield County.

His suit charged that the annexation was part of a conspiracy among the city's corporate and financial white leaders to dilute the growing political power of the city's blacks and unconstitutionally disenfranchise them.

Ultimately the federal courts ruled last August that the annexation, while it may have been tinged by racial considerations, was justified on other grounds. But it ruled that some sort of new apportionment was needed in the city to assure blacks a proper voice in their government. The ward plan was the result.

Today Richmond residents woke to the new realities of American urban politics, including the prohability that the new Council, when it meets for the first time next Monday, will elect a black mayor for this traditionally conversative city.

He is expected to be Henry L. March III, a civil rights lawyer in his 30s, who helped lead the fight to desegregate Virginia schools and who served on the previous Council as Vice mayor.

Nobody here pretends to know what all this will mean.

While Richmonders of both races are candid about the politics of race, most of the racial turmoil that struck other cities in the 1960s passed Richmond by.

"We've been trying for more than 10 years to get the blacks working (politically) with us," said Valentine, "but it's suited them politically to work separately. I certainly understand that, but I don't know what they're going to do now. They'll be able to do anything they want to do."

Valentine, generally regarded as one of Richmond's more dynamic and progressive officials, said he worries "that the economic facts of life" in the city won't mesh well with the campaign rhetoric of the new Council members.

"For example, nearly one-third of the real-estate tax paid in the city is paid by the people in my district. If the new Council runs those taxes up, they're going to drive the middle-class right out of the city. And if the middle class goes, the city goes," Valentine said.

But he said while there is some panic and fear among Richmond's more conservative white familes, there is more "watchful waiting."

"Much of the future," he said, "is going to depend on the tone set by this Council during the coming year."

Other reaction from whites was largely muted. The Richmond newspapers, often voices of racial stridency in the past, published polite and non-committal editorials of congratulations to the winners today and urged on them the spirit of "councilmanic cohesiveness."

Mayor-apparent Henry Marsh, weary and happy at the victory night, found case for nope in the apparent attitude of Richmond whites.

"There's been no real hysteria like there has been at times around here in the past," he said.

"Maybe some people have looked around at other cities and realized that blacks taking over isn't the end of the world," Marsh added.

He said at least one of the winners, Claudette McDaniel, received substantial white support.

"I think Richmond is now an oasis in the desert of conservatism that makes up the rest of Virginia," Marsh said. "I think we can be a good government and a good city, and maybe show the way to the rest of the country with our handling of urban problems."