Duncan B.M. Emrich, a professor of American folklore at American University and a former chief of the folklore section of the Library of Congress, died after a long illness yesterday at the Wisconsin Avenue Nursing Home. He was 69.

Born in Mardin, Turkey, in 1908, the son of American missionaries there, Prof. Emrich returned with his parents to the United States shortly before World War I.

A student at Phillips Academy in Andover, Mass, pro. Emrich received a bachelor of arts degree from Brown University in 1932 and a master's degree in English from Columbia University in 1933.

He next studied at the University ofMadrid in Spain, where he received his Doctor en Letras degree in 1934, after which he returned to the United States to enroll at Harvard University, from which he earned his doctorate in 1937.

Prof. Emrich became an instructor in English at Columbia University in 1937, which he held until he transferred to the University of Denver in 1940 as an assistant professor of English.

In 1943, Prof. Emrich joined the Army. He was commissioned as a first liertenant assigned to military intelligence, and after achieving the rank of major as the official American historian in the General Staffs office of the Allied Expeditionary Force, left the Army in 1945.

He was appointed chief of the Archive of the American Folk Song Section of the Libarary of Congress in 1945, and in 1946 became chief of the Folklore Section there, holding that position until 1955.

From 1955 until 1966 Prof. Emrich held various positions with American embassies in Greece, India, and Togo, and from 1966 until 1969 he served as a desk officer in the U.S. Information Agency in Washington.

Since 1969 he had been a professor of American folklore at American University.

For two years, from 1953 to 1955, Prof. Emrich had participated in NBC Radio's weekly program. "Weekend," on which he would speak about American folklore, customs, and superstitions.

During his career he also wrote several books on American West .

He is survived by his wife, Sarah of the home in Northwest Washington, and by his brother. Richard Stanley Merrill Emrich, Jr. former Bishop of the Episcopal Church of the Diocese of Michigan, who now lives in Sun City, Ariz.