The dissertation concentrating on the Chi thinking of Liu Ji-Shan is trying to explicate why the theory of the integration of Li and Chi can be the perfect teaching modality of Confucianism. Of all the interpretations as to the Chi thinking of Liu Ji-Shan, many researchers base their stances on Chi theory or Xinxue to explain his Chi thinking. However, the two viewpoints mentioned above are not sufficient to exhibit the complete contents of Liu Ji-Shan's doctrine, thus failing to show how the doctrine and other Neo-Confucianism theories differ in features. Therefore, the discourse of the dissertation takes the theory of Li and Chi as an inception and employs the “cutting off without cutting” thinking of the Tiantai perfect teaching as reference to justify the relationship between Li and Chi is not analytic or synthetic but paradoxical. Accordingly, Liu Ji-Shan ‘s Chi thinking becomes another new sect owing to the fact that his thinking entirely varies from Lixue and Xinxue in characteristics. The paradoxical identity, Chi thinking, becomes the perfect teaching of Confucianism as a result.