Dr. Roy J. Bullock, 76, who retired in 1972 as staff administrator of the House of Representatives Committee on Foreign Affairs, died Wednesday in his winter home in Marco Island, Fla., after a heart attack.

Dr. Bullock came to Washington in 1942 to join the Office of Price Administration. He later worked for the Board of Economic Administration before serving between 1945 and 1948 as an official with the U.S. military government in Germany.

He began his congressional career in 1948 as a member of the staff of the Joint Committee on Foreign Economic Cooperation. He joined the House Foreign Affairs Committee three years later as an economic expert. He later was promoted to senior staff consultant, served on the staff of the congressional delegation to the United Nations in 1957, then became staff administrator in 1970.

Dr. Bullock was a native of Crete, Neb., and was a 1925 graduate of Doane College where he was elected Phi Beta Kappa. He earned a master's degree in business administration at Harvard University in 1927 and a doctoral degree in economics at Johns Hopkins University in 1933.

He was a member of the faculty at the University of Oregon and at Johns Hopkins before becoming director of Johns Hopkins' school of business in 1941. He began his government career a year later.

Dr. Bullock was a resident of Arlington.

Survivors include his wife, the former Ruth France, of Arlington and Marco Island; two sons, Dr. Robert G., of Arlington, and John F., of Springfield; a daughter, Barbara Link of Arlington Heights, Ill.; seven grandchildren, and one great-grandchild.

The family suggests that expressions of sympathy be in the form of contributions to the Northern Virginia Heart Association.