The leaders of East and West Germany began three days of meetings here today. This is the first full round of discussions between government chiefs in more than 11 years and the first talks between the countries' top political leaders since the German nation was divided after World War II.

A West German Air Force 707 jetliner carrying Chancellor Helmut Schmidt landed at mid-afternoon at Schoenefeld Airport just outside the city limits of East Berlin. Schmidt was welcomed with a handshake and a smile by East German President Erich Honecker, who also heads his country's ruling Communist Party.

The talks here have no formal agenda and are meant to be as much of a free-wheeling discussion as possible. The Bonn government has stressed that no specific new agreements should be expected as an immediate result of these discussions but that perhaps the atmosphere between the two countries can be improved and relations put on a more normal basis.

These talks, however, come at a crucial time in relations between the entire East-West alliances. The East German government spokesman, Wolfgang Meyer, today described this visit as having "great political meaning," coming at a time when people in Europe are seeking peace and security and when relations between the two German states can help preserve both.

West German officials also say that the question of arms control in central Europe is certain to be a major topic of discussion.

Relations between the two countries are better now than they were at the peak of the Cold War in the 1950s and early 1960s. But they are still far from normal and the brief airport welcome was a stark reminder of just how unusual that relationship remains. There were no bands playing, no military guard to review and the only color visible other than gray at the cold snow-covered airport were two red-yellow-and-black flags of the two Germanys and a red carpet laid out for Schmidt.

All the rituals that help both countries cling to their view of the postwar world were scrupulously observed.

Schmidt's plane flew here by a roundabout route rather than those allowed by the victorious four powers of World War II -- the United States, Soviet Union, France and Britain. By landing at Schoenefeld, Schmidt avoided setting foot in East Berlin, which the communist government considers its national capital but which the West regards only as one zone of a divided city that would be the capital only of a united Germany.

There were no public arrival statements although the arrival was televised live by East and West German networks. Schmidt's picture and biography were given prominent display on the front page of the Communist Party newspaper here as the East Germans appear anxious that the visit boost their stock and Honecker's as important players on the world diplomatic stage.

The motorcade that carried the two from the airport to a former hunting lodge of Prussian kings near here also skirted the East Berlin city limits.

Schmidt seemed in a good mood, joking with photographers at the airport about how he maneuvered Honecker off the "red" carpet. Later, at the Hubertusstock Lodge where Schmidt will stay, he also said, perhaps in jest, that he and Honecker were not exactly "a loving couple" when photographers asked the two to move closer together.

The coming together of Schmidt and Honecker for three days of private talks is clearly a benchmark in the post-World War II history of the divided German nation of 61.3 million people in the West and 16.8 million in the East.

Eleven years ago, in March 1970, then-West German chancellor Willy Brandt broke the postwar ice with a visit to Erfurt in the East and a meeting with Willi Stoph, then East Germany's prime minister.

It was a meeting remembered most for the extraordinary emotion that the people of Erfurt showed for Brandt. They shouted "Willy, Willy" and despite the similarity in the sound of the names, it was clear who they meant. Stoph returned the visit two months later, going to Kassel in West Germany.

But at the time, the real power in East Germany was in the hands of Communist Party chief Walter Ulbricht. Honecker holds both the top party and government titles.

Schmidt and Honecker met briefly and informally in 1975 at Helsinki at the signing of the 35-nation agreement on cooperation in Europe and at the funeral of Yugoslav leader Josip Broz Tito in 1979. The two had twice planned to meet in 1980, but the meetings were postponed, first because of the Soviet invasion of Afghanistan and then because of tension in neighboring Poland.

Whether this meeting will have any practical or even emotional significance for the future of people on both sides of the border is unclear. One reason is the differing personalities and positions of the two leaders.

At 62, Schmidt is widely recognized internationally as one of the world's leading statesmen. A political pragmatist, he is known as a person of imagination who has left a mark on West Germany's postwar stability and direction. While firmly wedded to the NATO alliance, he undoubtedly has much more room to maneuver within that alliance than does Honecker within the Soviet-led Warsaw Pact.

Honecker, 69, is a survivor of 10 years as Communist Party boss and five as president. He is widely viewed by friend and foe as an apparatchik or bureaucrat rather than one of the more imaginative communist leaders.

In the Western view, he is weaker in both personality and position than Schmidt and therefore some in Bonn feel that the chemistry may not be the best for squeezing out the most long-term good from this meeting.

Nevertheless, both men are practical. While Schmidt is under some opposition pressure at home to show tangible gains, the wider hope is that the meeting itself will be a step toward a better understanding between the two leaders so that the relationship can at least be put on a more reliable basis.

There will be talk here of trade and the barriers still erected by the East to human contact with relatives in the West.

Schmidt hopes to persuade Honecker to reduce the amount of hard currency the East requires visitors to exchange to be allowed in. He also would like to see the rules eased under which the East Germans allow their citizens to leave. Such permission is now limited largely to pensioners.

East Germany is expected to press for continuation of the so-called "swing credit," basically an interest-free continuing loan of about $400 million that West Germany extends to East Germany for purchase of Western goods. While this is viewed as a benefit to the East, it also benefits many small and medium-sized Western firms that could not sell to the East without such credit.

Perhaps the key philosophical current running through the talks will be control of arms in central Europe.

This meeting was arranged within two weeks of Soviet President Leonid Brezhnev's trip to Bonn. After meeting with Schmidt, Brezhnev gave his blessing to Honecker for such a meeting. Then both Germanys moved quickly to avoid the kind of postponements that came last year and to reduce the time available for speculation about the meeting that could have raised expectations of specific results.

It is widely felt in the West that Brezhnev will ask Honecker to press the Soviet view on Schmidt of how negotiations between Moscow and Washington on limiting European-based nuclear weapons should be handled.

Schmidt is expected to try to impress Honecker that both men must work hard within their own alliances -- rather than against each other -- to encourage Moscow and Washington to reduce their armaments in central Europe as well as the confrontational tone of their relationship.

Schmidt is firmly tied to the U.S. position on the arms talks. But he also is acutely aware, his close advisers say, that when Soviet, American and German forces on both sides are considered, there are probably more troops, equipment and atomic weapons on German soil -- East and West -- than any other place in the world.

Thus he will argue, his friends say, that this situation can lead to catastrophe for Europe if the two superpowers ever collide. Therefore, if the two German states can, in their own way, encourage their respective alliances to negotiate toward an equilibrium that is less threatening, it is a valuable contribution to peace and protection for Europe.

Schmidt and Honecker will have lots of time alone, probably five sessions including long drives together to the hunting lodge some 35 miles north of East Berlin where Schmidt will be staying and a much longer drive to the northern town of Guestrow, where the two men will visit on Sunday.