Acute liver failure is one of the critical diseases in clinic.The authors combed through the thoughts of the past dynasties on Chinese medicine syndrome differentiation，combined with the understanding of modern medicine and then discussed the etiology，pathogenesis，therapeutic principle and treatment of acute liver failure in depth.The authors pointed out that the pathogenic qi becomes so excessive and the healthy qi becomes so deficient due to a rapid damage during a short period of time that the pathogenesis is characterized by the coexistence of"excess of pathogenic qi and deficiency of healthy qi".According to this，the authors put forward the basic therapeutic principle of"dispelling pathogenic qi mainly and reinforcing healthy qi simultaneously".The clinical treatment needs to start from the two aspects of dispelling pathogenic qi(clearing heat，resolving toxins，cooling the blood and dissolving stasis)and reinforcing healthy qi(supplementing healthy qi)，and should pay close attention to the rapid prognosis of the disease.The discussion provides reference for Chinese medicine in treating the acute liver failure.