CHEN Guyu was the first professor of Xiqu theory in Shanghai Theatre Academy after the Rearrangement of Colleges and Departments in 1952. He had made great contributions to studies of Kunqu Acting,the edition of scores,and the teaching of Xiqu history. Well versed in Chinese and Western theatre,he made in-depth research of Xiqu. On the basis of artistic practice,CHEN drew connections between theories and vivid theatrical images,and produced his unique theories on the Acting of Xiqu. CHEN’s research was praised by WANG Jisi,ZHAO Jingshen,WAN Yunjun,YU Lin,OUYANG Yuqian and other prominent scholars. CHEN had been a low-key scholar who pursued not fame but academic height. This paper discusses CHEN’s contributions to theories of Xiqu Acting.