Ruth L. Harris, 63, a former Department of Justice lawyer who was active in civic affairs in Accokeek, Md., died Sunday of cancer at Sibley Memorial Hospital.

Born in Washington, she earned a law degree from Washington College of Law, now part of American University. From 1941 to 1945 she was a lawyer in the criminal division of the Justice Department.

She and her husband, William S. Harris, moved from Washington to Accokeek, Md., in 1948.

Mrs. Harris was a neighborhood chairwoman of the girl scouts and helped establish 10 troops between 1959 and 1966. She also assisted in the organization of French language classes in the Accokeek elementary school.

She belonged to the Homemakers of American and the Accokeek Citizens Association.

She also was active in the Moyoane Association and the Alice Ferguson Foundation. These organization, devoted to the outdoor education of Maryland youth, have converted farmland on Maryland's Eastern Shore to campsites and nature trails.

In addition to her husband of the home in Accokeek, she is survived by a son, William J. III. of Chicago, and a daughter, June H. Sherren, of Minneapolis.

The family suggests that expressions of sympathy may be in the form of contributions to the Ruth Harris Memorial Fund of the Alice Ferguson Foundation in Accokeek.