Abstract： Chinese medicine believes that acne is related to internal injury of seven emotions， improper diet， overwork and so on，and is closely related to pathogensis of heat and fire. Professor JI Yunxi points out that acne patients have a constitution with yang deficiency syndrome，so such acne can be of yang deficiency and floating fire，with yang deficiency as its origin and floating fire as its superficiality. The floating fire is the fire from constraint，which is caused by the internal constraint of yang and the failure of yang to subdue. In addition，Professor JI believes that acne is also related to pathological products such as phlegm and stasis. Therefore，when Professor JI treats acne of yang deficiency and floating fire type，he often takes "using sweet and warm medicinals to remove heat" as the method，warming the kidney and assisting yang and taking into account the symptoms. His treatment warms yang to relieve constraint and subdues yang to the internal， and it also reinforces yang and inhibits yin， and treats both phlegm and stasis. In this way，the true yang can be supplemented，and yang qi subdues in the internal without floating on the external，making the spleen get transport，phlegm and damp not be generated，qi move and blood flow，and static blood not stagnate. As a result，acne can be gradually cured and will not recur.