Paul G. Kirk Jr., reaching out to a region that generally opposed his election as chairman of the Democratic National Committee, met here today with party leaders of the 13 southern states, some of whom said the national party might drag down strong state and local parties.

About 50 leaders from the 13 states, including 10 chairmen, told Kirk that a major problem is that the national party is perceived as being the captive of special interests, some of which were instrumental in his election as national chairman.

Kirk said, "The proliferation of caucuses makes diversity a weakness. And if caucuses are a reflection of politics by separation, that is a formula for defeat."

However, he added that diversity has been a strength of the party.

"We can't succeed if we turn our backs on the coalition that produced victory in the past," he said. "But if we don't succeed as a whole, then no element of the party does."

In a 2 1/2-hour meeting, the southerners urged the national party to concentrate on issues of major concern to average Americans to override party factionalism. They said the national party has nominated presidential candidates too liberal to be elected. And they emphasized moderate positions on the economy, a strong national defense and a competitive posture in international trade.

"The Democratic Party in the South is up for grabs right now," said former Georgia governor Carl Sanders. "The Republicans have their best opportunity ever because many people who vote in Democratic primaries for local candidates here feel less commitment to the Democratic Party as such than ever before.

"We need to get those voters that Ronald Reagan is reaching -- young people and suburban housewives, people who don't belong to organizations or caucuses that make them feel committed to the party."

Sanders said the Democratic Party used to be the party of "actors and action, but it is now a party of reaction to Republican initiatives." He cited House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) as a party leader who primarily reacts to Reagan's initiatives.

"The party needs to get away from the perception that the cumulative weight of its caucus and special-interest groups causes it to nominate liberal presidential candidates," said Georgia State Democratic Party Chairman Bert Lance. "Perhaps only Paul Kirk can deal with that problem because he's from the northern liberal wing of the party and has labor support."

Kirk, whose election was opposed by about two-thirds of the southern members of the DNC, scheduled this meeting shortly after his election.

The new party chief is to meet with Democratic leaders from the western states in late March or early April. Several of the southerners said they were "delighted" to meet with Kirk.

"Paul reached out a hand to the South, and we're delighted because we have felt left out in the past," said Alan Diamonstein, the Virginia State Democratic chairman.

Kirk, who went from here to Plains, Ga., to call on former President Jimmy Carter, said he felt "a special obligation and opportunity to come here." Kirk is a Massachusetts native and a longtime associate of Sen. Edward M. Kennedy (D-Mass.).

"I come from a different part of the country which has a shrinking base as political strength moves to the South and West," Kirk said after the meeting. "I came to listen and learn from those who have elected so many Democrats to office at every level."

Kirk said caucuses had proliferated within the DNC because people felt that organizing as caucuses was the only way they could make themselves heard.