In TREATISE ON FEBRILE DISEASES，Taiyang disease and Yangming disease can be classified into Meridian syndrome and viscera syndrome，but few people pay attention to whether Shaoyang disease can be classified. This paper firstly clarifies Meridian syndrome and viscera syndrome's definitions by discussing the origin and development of them. Then，based on the original book TREATISE ON FEBRILE DISEASES and its background，it is shown that the differentiation of six meridians of febrile diseases is consistent with the idea of "viscera"，which is the core in NEIJING，and the transmission and transformation of external pathogens must be a process from meridians to viscera. Analysising Taiyang and Yangming's meridian and viscera syndrome，Shaoyang can also be classified. Combined with the specific provisions in the book，Shaoyang meridian is Xiaochaihu Decoction syndrome and Shaoyang viscera syndrome includes Chaihu Guizhi Ganjiang Decoction syndrome and Dachaihu Decoction syndrome. Connected with the current clinical syndrome，the treatment of Shaoyang Meridian and viscera syndrome can be more widely used in clinical practice.