Abstract： This paper briefly analyzes LIU Wansu's academic thought of five circuits and six qi from three aspects： supplementing the pathogenesis of five circuits and six qi， creating “fire- heat theory” and establishing the system of differentiation and treatment of “harmful hyperactivity and responding inhibition”. According to the analysis，LIU Wansu's Suwen Xuanji Yuanbingshi follows the principle of the change of five circuits and six qi in heaven and earth. Based on “pathogenesis item 19” in Huangdi Neijing， LIU Wansu proposed that “six exogenous pathogenic factors transfer from fire” and “excess among the five minds transforms into heat”，and created “fire-heat theory”，which supplements and develops the pathogenesis theory. According to the responding inhibition of five phases among six qi， he put forward “concurrent transformation where phenomenon appears contrary to the essence”，“transforming to the phase that is not restricted ” and “discharging the hyperactive qi”， as well as established the system of differentiation and treatment of “harmful hyperactivity and responding inhibition”. LIU Wansu respected the ancient theory but was not restricted by it. While developing the pathogenesis theory，he also inherited the theory of five circuits and six qi，which plays an important guiding role in clinical differentiation of pathogenesis and treatment of disease.