By studying the knowledge of scholars from China and Japan on ,Treatise on Exogenous Febrile Diseases, the authors’ different views are expressed. It is believed that "exterior-interior and inside-outside" have their own meanings and cannot be mixed. "Exterior-interior" refers to syndromes, and "inside-outside" refers to symptoms. "Exterior-interior" refers to the subjective summary of all external or internal symptoms, and "inside-outside" refers to a description of a specific objective symptom. It is considered that the "external syndrome" in ,Treatise on Exogenous Febrile Diseases, is "external symptoms of the human body" .