An exultant Mayor Marion Barry yesterday declared his landslide victory in Tuesday's Democratic primary chiefly a triumph of his personality over voter disenchantment with shortcomings in his administration.

Lawyer Patricia Roberts Harris and two other challengers may have scored points from time to time, Barry acknowledged. But they couldn't overcome a network of supporters he has developed since his days as a street activist in the late 1960s, he said, and they couldn't rival his knowledge of local politics and organizing techniques.

"Marion Barry is personally rather favorably looked at by the electorate, even though people might have some serious problems about agencies or about the government and how it works or doesn't work in some areas," Barry said during a post-election press conference at the Capital Hilton Hotel, where he and his supporters had celebrated the night before.

It was a somewhat ironic statement from Barry, whose reelection drive included well-timed, last-minute improvements in city services that effectively nullified opponents' accusations of incompetence, inefficiency and lack of responsiveness in his administration.

Still, chastened by campaign criticism of his first term, Barry pledged yesterday to shake up his administration after the Nov. 2 general election, to improve the city's criminal justice system and step up efforts to create jobs and stimulate commercial development.

He also said he was willing to consider some of the ideas advanced during the past nine months by Harris and City Council members John Ray and Charlene Drew Jarvis, the other two Democratic challengers.

Among those ideas, he said, is Harris' proposal to require all children in the city to begin school at age 3, instead of age 5 as now required.

"I don't want to finish my second term just embroiled in controversy and not be able to look back in four years and say, 'Here are the things that the Barry administration achieved for and with the people of the District of Columbia,' " Barry said.

Barry, who rose to prominence as a member of the D.C. school board and City Council, emerged from Tuesday's primary as unquestionably the most powerful figure on the city's political landscape.

He captured 59 percent of the Democratic vote, sweeping to victory in seven of the city's eight wards and dispelling any lingering notions that his 1978 primary victory over Sterling Tucker and Walter E. Washington was a fluke.

While the Board of Elections and Ethics had neither complete returns nor ward-by-ward breakdowns yesterday, an analysis of the most thorough returns available indicated that Barry won seven of the city's eight wards, and nearly 100 of the 137 precincts. He lost in 30 precincts and no returns were available for the remaining 10.

Barry lost 18 of those precincts in Ward 3, seven in Ward 2 and two precincts in the Capitol Hill area of Ward 6 -- largely white areas of the city that he won in the close three-way competition in 1978. Barry won only one precinct in Ward 3 Tuesday: Precinct 29 around the Sidwell Friends School on Wisconsin Avenue NW.

Harris won many of the precincts in Ward 3, the largely white and mostly affluent section of the city west of Rock Creek Park. But she won them by narrow margins -- 21 percentage points in Precinct 50 (Chevy Chase Community Center), for instance, and 16 points in Precinct 51 (Lafayette School).

But Ward 3, where voter turnout is usually among the highest in the city, did not give Harris enough of a margin of victory to outdistance her losses to Barry elsewhere in the city.

Barry won some precincts in other wards by as much as 50 percent, notably in Ward 7, where the mayor moved after his 1978 race with an eye to developing a black political base for this year's election.

That ward, which straddles far Northeast and Southeast Washington and is populated with a large number of small businesses, schoolteachers and other city employes, gave Barry his strongest support Tuesday.

In 17 of the 21 precincts in Ward 7, he won by an average of 46 percentage points. It made no difference if the neighborhoods were the relatively affluent areas to the south of Fort Dupont Park, where Barry lives, or among the working-class areas and public projects in the northern end of the ward.

For example, in his home precinct, 110, around Anne Beers Elementary School, Barry received 69 percent of the vote compared to 25 percent for Harris.

He won by almost identical margins in Precinct 103 around Plummer Elementary School north of the park and farther east, at Merritt School at 50th Place and Hayes Street NE, an area with a large number of public housing tenants.

In Wards 4 and 5 in upper Northwest and Northeast, areas with high percentages of voter turnout and strong black, middle-class communities that Harris had hoped to develop as a political base, Barry trounced her.

She lost in her own neighborhood, precinct 62 around Shepherd Elementary School, by 50 to 39 percent, and lost several other precincts in Ward 4 by margins twice as great.

In precinct 66 around Backus Junior High School in ward 5, the city's largest precinct, Barry defeated Harris by a 2-to-1 margin, results that were mirrored in other sections of the ward.

That outcome was repeated throughout the inner city with Harris limited to conquests on Capitol Hill and Foggy Bottom.

The change in Barry's support since his narrow victory in the 1978 primary is striking. In some precincts of Ward 4, for instance, Barry's percentage of the vote this year was double his share in 1978, when Sterling Tucker carried the ward.

Yet in Ward 3, the largely white and mostly affluent section of the city west of Rock Creek Park, Barry's support Tuesday was significantly below his showing in 1978, when Ward 3 gave him an overwhelming number of its votes.

Ivanhoe Donaldson, Barry's campaign manager, disputed any suggestion that Barry's political base had changed dramaticially since 1978, when his scant margin of victory was provided by voters in Ward 3 and the inner city.

Donaldson contended yesterday that the closeness of the 1978 race, which Barry won with 35 percent of the vote, obscured the fact that Barry enjoyed substantial support among blacks throughout the city -- support that has grown during the past four years.

"His political base didn't change, it expanded," Donaldson said.

During a separate interview in his hotel suite yesterday, where he relaxed with campaign aides, Barry said that many of Harris' problems stemmed from her reliance on a campaign staff that had little experience in local politics.

"We had all the organizers who knew about organizing for real," Barry said. "Pat had some people, but several of them were out-of-towners. You can have all the techniques and skills you want to about how you organize, but unless you've been in this town you don't know who to call and who not to call."

Barry said that Harris also failed to capitalize on potential support among women voters and mistakenly assumed she could beat Barry in Ward 4, where she lives, and adjoining Ward 5, because of the relatively high number of middle- and upper-income blacks who live there.

"People in Ward 4 are very diverse, with incomes ranging from $5,000 to $100,000," Barry said. "There's a difference between the people on the east side of Georgia Avenue and those on the west side of 16th Street. Everybody assumed because Pat lives in Ward 4 that people would naturally relate to her. But it's not so."

Barry said that his opponents and the news media underestimated his popularity, even at the height of the city's budget problems, when he had to lay off city workers and cut back on services.

He said he developed a large network of friends and supporters, dating back to the late 1960s when he helped found Youth Pride Inc., a self-help organization for the city's down-and-out.

"People have respect for me in terms of taking on some real tough guys and some real tough situations," Barry said, in recalling his efforts to help young black men with prison records find jobs.

"And I know so many people in this town," he added. "It's amazing. And that was part of the problem of any challenger . . . I think if you know me, it's harder to be against me than if you don't know me."

The mayor also claimed that criticism that he exploited his office to win reelection by tailoring his budgets to satisfy constituents, by appointing allies to key boards and commissions, and by approving generous new contracts for city employes, was exaggerated.

"There are burdens and benefits to the incumbency," he said.

Barry contended yesterday that he had considerable support among city employes even before he granted new contracts that included such bonuses as free eye and dental care and a provision that for the first time allows a check-off system for union dues.

"Just as I'm personally popular with a number of citizens, I'm personally popular with a number of D.C. employes," Barry said. "Now I can go to a meeting where people are mad as hell at their supervisor about something, but they're not mad at me . . . The contract was like icing on the cake . . . The cake was already baked."