TAN Si-tong's Doctrine of Humanness(Ren Xue) is a product of the comprehensive influence of Chinese and foreign intellectual traditions and the construction of its basic concepts reflects the confounding effect of different traditions. For example, the concept of "Heaven" in Ren Xue not only contains the traditional Confucian intellectual factors, but also is deeply influenced by Christianity and Buddhism. With the assistance of the Christian concept of "Heaven", TAN Si-tong reconstructs the concept of "Heaven" as the basis of human ethics in traditional Confucianism and transforms it into a metaphysical principle to demonstrate political, ethical and social equality. However, the Christian concept of "Heaven" with the God as an entity is de-substantiated in Ren Xue. In this process, the Buddhist thought of breaking the dharma attachment to "Heaven" in The Treatise On the Perfection of the Doctrine of Consciousness-Only(Cheng Weishi Lun) plays a direct role.