Student at Peking University, went to the USA in 1947, where he read English at Yale University. Received Ph.D. in 1951. Between 1952 to 54, he was a researcher at Yale, and started his work in the history of modern Chinese literature. He taught in Peking University, Michigan State University, New York State University and Pittsburgh State University. In 1969 was appointed Professor of Chinese in the Department of East Asian Languages and Cultures at Columbia University. At his retirement in 1991 he was appointed Emeritus Professor of Chinese; Sinologe, Philologe, Literaturwissenschaftler