Various kinds of cultural, philosophical and literary discourses emerging during the May Fourth Movement in China came from the ideology of reform of the late Ching Dynasty and was then better developed. On the basis of democracy and science, the spirit of the Movement searched for the reform of the individual, including autonomy, equality and independence. The social movement was relevant to the global tendency of Humanism in the 20s and 30s. Under the circumstances, Chou, Tso Jen, in the first place, was concerned with the human-being. The claim for human rights ranged from the individual and female rights to children's issues, which was regarded as a breakthrough in Chinese history. As a pioneer of the May Fourth Movement, Chou, based on the Han culture, constructed with a goal of liberating the body and the soul, the Human Studies and Gender Studies through criticism and translation. His everlasting and profound concerns were beyond all those who got involved in the Studies above in his epoch. This essay aims to analyze the source and development of Chou, Tso Jen's Human and Gender Studies and to examine his life-long declaration.