The Rev. W. Curtis Draper Jr., 69, rector emeritus of Trinity Episcopal Church in Upper Marlboro, died Monday at Johns Hopkins Hospital in Baltimore. He had suffered from a liver ailment.

Mr. Draper was born in Washington and graduated from McKinley High School here. He graduated from George Washington University and then from General Theological Seminary in New York. He was ordained in 1935.

He was rector of Christ Church in Port Tabacco Parish in La Plata, Md., before joining the staff of Washington Cathedral in 1941. At the cathedral he was canon precentor, a post in which he was responsible for arranging worship services as well as pastoral duties. He became rector of Trinity Church in Upper Marlboro in 1947, and retired in 1975.

Upon his retirement, the vestry elected him rector emeritus.

In addition to pastoral duties, Mr. Draper held many posts in the Diocese of Washington. He was elected to represent the diocese at three general conventions of the Episcopal Church. His most recent assignement was as a member of the ecclesiastical court of the diocese.

He was a member of the Prince George's County Welfare Board, the County Juvenile Court Advisory Committee, and the county Commission on the Aging. He also was a member of the Lions Club.

Surviviors include his wife, Eva Mae, of the home in Upper Marlbor; two sons. William C. III, of La Plata, and George Angus, of Oxon Hill; a daughter, Mary Alice Blankenbaker, of Seat Pleasan, and seven granchildren.

The family suggests that expressions of sympathy be in the form of contributions to the W. Curtis Draper Jr. Memorial Fund, Trinity Episcopal Church, Upper Marlboro.