Harold I. Baynton, 74, a former assistant attorney general and aide to Sen. Howard W. Cannon (D-Utah), died Sunday of diabetic complications at Sibley Memorial Hospital.

Mr. Baynton worked for the Justice Department from 1940 to 1952, first as a lawyer, then as legislative counsel, and finally, from 1950 until he left the department, as assistant attorney general and director of the Office of Alien Property.

He later practiced law and worked in private industry in the area. He returned to government service in 1955 as chief counsel of the Senate Commerce Committee, a post he held for eight years.

He served on Sen. Cannon's staff from 1971 until his retirement in 1973.

Mr Baynton, a native of Montana, came to Washington in 1936 and earned a law degree at the Washington College of Law.

He belonged to the American and D.C. bar associations and the Association of Former Senate Aides. He also was a governor of the National Aviation Club and a trustee of American University.

He is survived by his wife, Gladys L. (Dee), and a daughter, Carol B. Phelps, both of the home in Bethesda; a sister, Harriet Anderson, of San Leandro, Calif., and one grandchild.