The theory of "yin fire" was first put forward by Li Gao,a famous physician in the Jin Dynasty,on the basis of studying the theory of Neijing.However,the generation and nature of "yin fire" make the doctors of all ages argue endlessly.The theory of "yin fire" has been paid increasingly attention in the diagnosis and treatment of difficult diseases.This paper returns to Dongyuan’s Treatise on Spleen and Stomach and Differentiation on Endogenous and Exogenous Diseases,and makes a brief analysis on the generation,essence,clinical manife...