James Randlett Fowler, 56, a foreign affairs officials of the U.S. Agency for International Development, died of cancer Sunday at John Hopkins University Hospital in Baltimore.

Mr. Fowler, a native of Boulder, Colo., and a 1943 magna cum laude graduate of the University of Colorado, joined the State Department in 1950 as a foreign affairs officer specializing in U.N. activites. He had just completed two years at Oxford University in England as a Rhodes scholar, receiving degrees in politics, philosophy and economis.

After three years at the State Department, Mr. Fowler joined the international division of the Bureau of the Budget, working on economic assistance programs for the Middle East. Later he joined the old International Cooperation Administration, which was responsible for U.S. foreign assistance programs.

This began a long career in administration of overseas AID programs. In 1961 he was named deputy assistant administrator for AID's Far East bureau. He later became AID mission director to Columbis, where he was responsible for the direction of the U.S. foreign aid. After three years in that capacity, he served as deputy U.S. coordinator for the Alliance for Progress.

In 1970, Mr. Fowler became a member of the Senior Seminar in Foreign Policy at the Foreign Service Institute of the State Department.

After that one-year appointment, he was named special assistant to the AID administrator and became executive director of the agency's Committee on Environmental Development. He continued to serve as special assistant to the administrator and deputy administrator until his recent illness.

Mr. Fowler had served in the Army for three years. He then taught English at the University of Colorado. It was then theat he was awarde a Rhodes scholarship.

Survivors include his wife, Margaret Williamson Fowler, a daughter, Deborah, and son, Michael, all of the home in Chevy Chase; another daughter, Pamela of Columbus, Ind., and three brothers , William and Knox, both of Colorado Springs, and Samuel of Miami.

The family suggests that expressions of sympathy be in the form of contibutions to the Johns Hopkins Oncology Center, John Hopkins Hospital, Baltimore.