Deputy Secretary of State John C. Whitehead leaves for Eastern Europe and the Soviet Union today on an 11-day trip to explore changing relationships in Eastern Europe and Moscow's human rights policies on the eve of next month's U.S.-Soviet summit meeting.

Whitehead will be the highest-ranking U.S. official to visit East Germany since relations were established with that country in 1974, according to the State Department. He also will go to Hungary, Yugoslavia and West Germany before going to Moscow for talks on human rights.

Whitehead's East European trip is intended to signal U.S. readiness to improve relations with countries of the Soviet bloc on the basis of "differentiation" between regimes, a State Department official said. The exploration of bilateral and international issues takes on particular importance as those nations seek more "breathing room" under policies announced by Soviet leader Mikhail Gorbachev, officials said.

In a speech in Moscow Wednesday, Gorbachev signaled new Soviet flexibility in relations with Eastern Europe, calling for a "more sophisticated culture of mutual relations" among communist countries and suggesting that Moscow will ease its dictation to satellite nations.

More than a year ago Whitehead took on special responsibility for U.S. relations with Eastern European countries. In East Berlin, Whitehead is expected to meet longtime East German leader Erich Honecker, who recently completed a long-awaited and much-postponed visit to West Germany, the first such visit there by a top East German.

The Whitehead visit occurs after a trip to East Germany last July by Assistant Secretary of State Rozanne L. Ridgway, who is a former U.S. ambassador to East Germany, and after a meeting at the United Nations Sept. 23 between Secretary of State George P. Shultz and East German Foreign Minister Oskar Fischer.

In a related development, the House Foreign Affairs Committee yesterday adopted a resolution asking Honecker to demolish the Berlin Wall and cancel East German border guards' shoot-to-kill orders.

Last November, Whitehead visited Hungary and Yugoslavia. The latter broke out of Soviet domination three decades ago.

Whitehead's exploration of human rights policies in Moscow grew out of a proposal made here last Friday by Soviet Foreign Minister Eduard Shevardnadze. The human rights discussion is one of several high-level U.S.-Soviet meetings planned in preparation for the Washington summit of President Reagan and Gorbachev scheduled to begin Dec. 7.