Yee started teaching at the Department of Geography and History and Department of History in February 1949. He taught history of the Ming and Qing period, modern Chinese history, contemporary Chinese history and history of transport in the East and West. He served as the second dean of the College of Liberal Arts from 1959-1962.

Contemporary Chinese History, Oral History

In 1955, Kuo was appointed to establish the Institute of Modern History of the Academia Sinica. In 1965 the Institute of Modern History was founded. In the founding period, apart from working with the Ministry of Foreign Affairs and the Ministry of Economic Affairs to acquire substantial valuable records and complete the historical works "Files of Naval Defense", "Files of Mining" and "Records of Negotiations between China and France over Vietnam", he also actively promoted the work of oral history. He held interviews in person and edited drafts of 59 people. He was elected at the 7th Convocation of the Academia Sinica in 1968 as an Academician in the Division of Humanities and Social Sciences.