Charles H. Jennings, 76, a retired government engineer who had lived in this area for nearly 30 years, died Tuesday at Suburban Hospital in Bethesda. He had cancer.

Mr. Jennings began his government career as a civil engineer with the U.S. Geological Survey in Missouri in the early 1930s. He later worked in Missouri for the Army Corps of Engineers and the Rural Electrification Administration.

He spent a short time with the REA in Washington in 1943, then went to Billings, Mont., with the Interior Department's Bureau of Reclamation.

He returned to Washington in 1951 as a civilian electrical engineer with the old Potomac River Naval Command. He worked for the old D.C. Sanitary Engineering Department for 10 years before joining the Public Buildings Service of the General Services Administration in the mid-1960s. He retired from the GSA in 1972.

He had been active in a number of professional organizations, including the American Society of Civil Engineers, the Institute of Electrical and Electronics Engineers and the Washington Society of Engineers.

Mr. Jennings was a native of Oklahoma and a graduate of the University of Missouri, where he earned a bachelor's degree in civil engineering in 1930. o

He was a member of All Saints Episcopal Church in Chevy Chase. He was a member of the Columbia Country Club and the Fossils. He had resided in Chevy Chase since 1958.

Survivors include his wife, Pauline W., of Chevy Chase; a son, John A., of Harrisburgh, Pa.; a daughter, Barbara J. Courtney of Denver; a sister, Lucille Whitaker of Hemet, Calif.; four grandchildren, and one great-grandchild.