This thesis tried to describe how inner nature(inner moral value) is handed down with connection to thought together with explanation of 'Daotonglun(道統論 the theory of Succession of the Way'). There is 'Daotonglun(道統論)' in Confucianism in which the process of inheritance of Confucian inner nature(inner moral value) is arranged in terms of genealogy. Daotonglun maintains that the genealogy of Daotong(道統 Succession of the Way) handed down by various main confucian thinkers since Yao(堯) and Shun(舜) is the succession of legitimate Confucian inner moral value. Though there is misunderstanding that Daotonglun originated from Chanzong's(禪宗) idea of Fasi(法嗣), it is an idea peculiar to Chinese Confucianism formed through Mengzi(孟子), Hanyu(韓愈) and Zhuzi (朱子). Despite Daotonglun is the Confucian genealogy of succession of inner moral value, the existing research of Daotonglun is not sufficient in explaining the connection of thought among the figures who compose the genealogy of Daotong. This thesis tried to explain, though in short, the genealogy of Daotong, C o f u c i o u s ( 孔子) - C e n g z i ( 曾子) - Z i s i ( 子思) -Me n g z i ( 孟 子)-Neo-Confucianism in Song(宋) dynasty, in terms of connection of thought among them. Followings are the contents. The Ren(仁) of Kungtzu was understood and handed down by Cengzi as a mental principle, Zhongshu(忠恕), and then deepened into the idea of Xing (性 human nature) by Zisi. Succeeding to Zisi's thought, Mengzi maintained Jinxingzhitian(盡性知天) thought and in Han(漢) and Tang(唐) dynasty after Mengzi, inner inquiry was suspended. In Song(宋) dynasty, the inner pursuit was again succeeded, Li-Qi philosophy(理氣哲學) was established and Jing(敬) thought was developed as a mental principle.