From the viewpoint of the history of thoughts, the academic studies of the Qing (清) Dynasty are opposite to the mainstream thoughts of Neo-Confucianism in the Song (宋) and Ming (明) Dynasties, which suggests preserving the Heavenly principle (the moral values) and discarding human desires. Instead, it develops towards a direction that values "Qi" (氣) and "Qingyu" (情欲, desire) and emphasizes traditional Confucianism, focusing on "being erudite in classic literatures" and "studying numerous and varied knowledge." Wang Chuan-shan (王船山), living from the end of the Ming Dynasty into the early Qing Dynasty, and Dai Dong-yuan (戴東原), living during the reign of Qianlong (乾隆) and Jiaqing (嘉慶), are considered two important and representative scholars in the Qing Dynasty with influential doctrinal theories on "Qi." What are the similarities and dissimilarities between the thoughts of these two thinkers? This thesis not only intends to compare the philosophical doctrines between Chuan-shan's and Dong-yuan's from three issues: moral metaphysics, humanity and practical theory, but also attempts to make a detailed analyses of their viewpoints and to clarify the implications of these two thinkers' arguments and the characters of their thoughts.