Lloyd B. Harrison, 91, special assistant corporation counsel for the D.C. Public Utilities Commission for 23 years before his retirment in 1960 as the commission's chief attorney, died Thursday at the Presbyterian Home of D.C. He had a heart ailment.

Born in Duncan, S.C., Mr. Harrison earned bachelor's and law degrees from the University of South Carolina. He was elected to the state legislature while attending law school and subsequently served three terms. He served as a municipal court judge and had a private practice in Greenwood, S.C., before moving to Washington in 1925 as a lawyer for the Interstate Commerce Commission. He joined the staff of the D.C. Corporation Counsel in 1937.

At his reappointment in 1959 at the age of 70 to an indefinite term as the Public Utilities Commission's senior legal adviser, Mr. Harrison was given a Certificate of Merit in ceremonies held at the District Building.

An Army veteran of World War I, Mr. Harrison was wounded during the Meruse-Argonne campaign and awarded the Purple Heart.

He and his wife of 62 years, the former Lucile Stoney, lived in Washington before moving to Sebastian, Fla., in the early 1960s. They returned to his area in 1978, when they moved to the Presbyterian Home.

Mr. Harrison was a charter member of the Barristers Masonic Lodge here, a vice commander of the American Legion, a member of the Knights of the Round Table International and a former president of its Washington chapter, and a former deacon in the Church of the Pilgrims in Washington.

Besides his wife, survivors include a daughter, Isabel H. Coll-Pardo of Bethesda; a son, Dr. Lloyd B. Harrison Jr. of Wilmington, Del.; eight grandchildren and one great-grandson.

The family suggests that expressions of sympathy be in the form of contributions in his name to the University of South Carolina, Columbia, S.C.