The Rev. Alfred St. John Matthews, 70, rectorof St. John's Episcopal Church, Langley Parish, in McLean, died Friday at his home in McLean after apparently suffering a stroke.

He came to Northern Virginia in 1943 to become rector of St. John's as well as Holy Comforter Church in Vienna and St. Michael's Church in Arlington. He had devoted himself solely to St. John's since 1947.

Mr. Matthews was a member of the executive committee, the department of missions and the standing committee of the Diocese of Virgina. He was dean of the North Fairfax region of the diocese during 1972-76, and was considered "the dean" of the McLean Cleary Association.

Mr. Matthews was a graduate of the University of the South in Sewance, Tenn, where he earned a bachelor of divinity degree in 1934. He was ordained in his native city of Jacksonville, Fla, that year.

Before coming here, he had churches in Monticello and Perry, Fla, and Macon and Thomaston, Ga.

He is survived by his wife, Willa Douglas Perry Matthews, of the home; a son, Alfred Jr., of Atlanta, Ga; two sisters, Mrs. D. P. Gandy, of Tallahassee, Fla, and Mrs. Lewis McLendon, of Jacksonville; two brothers, Frank B., of Saint Augustine, Fla, and William Douglas, of Oklahoma City, and two grandchildren.