Lillian Zehner Bradbury, 64, the chief clerk at the Bethesda branch of the Montgomery County Public Library, died of cancer Aug. 9 at the Bethesda Naval Medical Center.

Mrs. Bradbury and her husband, John D.,a retired lieutenant colonel in the Marine Corps who died in 1967, had lived in Bethesda since 1953. She joined the Montgomery library system in 1965 and was made chief clerk of the Bethesda branch in 1973.She helped the branch relocate in an expanded facility in 1976.

Mrs. Bradbury was born in Zelienople, Pa. She attended Temple University in Philadelphia and later worked in the Pennsylvania State Department of Public Instruction in Harrisbury. She was commissioned in the Marine Corps during World War II and was stationed at Quantico, Va.

She had been active in senior women's organizations at St. John's Episcopal Church in Bethesda.

Mrs. Bradbury's survivors include a son, John D. Jr., of Silver Spring; two daughters, Diana B. Sessions, of Wheaton, and Barbara R. Bradbury, of the home in Bethesda; five sisters, Mary K. Stunkard, of Zelienople, Christine Hutchinson, of Oakville, Ontario, Marjorie Barnes, of Meadville, Pa., Amy Wilkinson, of Rochester, N.Y. and Jo Ann Freshcorn, of Matthews, N.C., and three grand children.