this thesis is aimed at revealing the continuity and the discontinuity between Zhuzixue(朱子學) and Xianshanxue through a point of dispute about Taiji. Zhuxi regards T매 i as the model that everyone should follow. Taiji in his thought is the universal Li and the nature of all things in the universe. Therefore, he says everyone should know and realize its principle given from Heavenl. this is the Zhuzixue’ s feature that gives special emphasis to Li been inlmanent in all things in the universe. On the other hand, Lu Xiangshan lays the emphasis on one\'s innated ‘mind and heart’ that is a pole as the Zhong(中) So, he says everyone should not lose one\' s innated mind and heart. ll1erefore, he regards the precursor’ s role as important because the precursor embodies his own innated mind and heart. We can fincl the difference of the existentialism and the theory of Gonfu in two schools through a point of dispute about Taiji.