Henry A. Kissinger '50, professor of Government and frequent advisor to Presidents, has been appointed special consultant to Ambassador Henry Cabot Lodge in Vietnam.

Kissinger, who is taking a sabbatical leave this year, left the country Friday and will remain in Vietnam until November 10, Robert L. McCloskey, State Department press officer, said this weekend. McCloskey would not speculate on Kissinger's duties but said he would be directly responsible to Ambassador Lodge.

Lodge personally requested Kissinger's services, Thomas C. Schelling, acting director of the Center for International Studies, said last night. "The appointment has been arranged for a month," Schelling noted. "But no one at Harvard knows whether Kissinger will be working out of Saigon, tramping the jungles, or holed up on an aircraft carrier."

Schelling said that Kissinger and Lodge met at the 1964 Republican Convention, when Kissinger was attached to Governor Rockefeller's campaign staff.

The author of several influential texts on foreign policy, Kissinger has often been consulted by the federal government. In 1961-62, he commuted to Washington to serve as President Kennedy's special advisor on underveloped nations. Kissinger also advised the National Security Council and the Department of Defense under the Eisenhower and Kennedy administrations.