In the Song Dynasty Daoism was important and very prosperous, and in this background the Daoism study on Lao Zi developed into a new phase. The doctrinal interpretation of Lao Zi is strengthened, the theory of disposition was explained and developed, and the thoughts of Confucianism, Buddhism and Daoism were integrated, etc. These main characteristics of the development of the Daoism study on Lao Zi not only reflected the new change of the Daoism doctrine and the thoughts in the Song Dynasty, but also typically represented the academic spirit of the Song Dynasty.