"Treating different diseases with the same method " is one of the important parts of ZHANG Zhongjing’s theory system of treatment based on pattern differentiation. It is also the theoretical foundation for dealing with refractory diseases with simple but effective methods. The premise of "treating different diseases with the same method"is the same pathological mechanism. According to similarities and differences in the process of the development of diseases

it can be categorized into "treating different diseases of same syndrome with same treatment"and"different diseases of different syndromes with same treatment". In Treatise on Febrile and Miscellaneous Diseases（ 伤寒杂病论）

Gancao Xiexin Decoction is applied in the treatment of Fox Creeper（ Behcet’ s disease） and Glomus Belowthe Heart（ epigastric fullness）

which reflects the theory characterized by "treating different diseases with same method". To grasp the application mechanism treating Fox Creeper and Epigastric Fullness with Gancao Xiexin Decoction extends the indications of "treating different diseases with same method"with Gancao Xiexin Decoction

and provides basis for the clinical treatment of diseases with high efficiency.