Robert M. Paul, 56, an environmental and economic development specialist with the House Committee on Public Works and Transportation, died of cardiac arrest Wednesay at Fairfax Hospital.

He had been staff director of the committee's subcommittee on economic development since July, 1973.

Mr. Paul had served as deputy assistant secretary of interior for management of fish and wildlife resources from 1961 to 1967, when he joined the Department of Housing and Urban Development. He was director of HUD's urban growth policy division from 1971 to 1973.

He was born in Huntington, Ind. He grew up in Riverside, Calif. He graduated from the college of engineering at the University of California at Berkeley and took graduate work in management and ecology.

Mr. Paul was staff assistant to the director of California's department of fish and game before coming to Washington in 1956, when he became executive secretary of the Sport Fishing Institute, a position he held until joining the Interior Department. He lived in Springfield, Va.

During World War II, Mr. Paul was a bombardier with the U.S. Eighth Air Force in England. He earned the Distinguished Flying Cross and the Air Medal with three Oak Leaf Clusters.

He is survived by his wife, the former Mabel Murfee, of Springfield; a daughter, Marjorie Paul-Shook, of San Francisco; three sons, James, of Carbondale, Ill., Kenneth, of Globe, Ariz., and Mark, of Springfield; his parents, Mr. and Mrs. Mark L. Paul, of Riverside, and a sister, Anita Jorgenson, of California.

The family suggests that expressions of sympathy be in the form of contributions to the Springfield-Franconia Host Lions Club.