Abstract： Objective　To investigate the effect of endotoxin on rats liver mitochondria and the　therapeutic action of Chinese medicine 912．Methods　Endotoxemic rats were randomly divided into four groups：endotoxin group；912 group：normal group and the control．8 cases of animals were included in each group．Mitochondria superoxide was measured in mitochondria and so　were　plasma GSH-Px，SOD 6 hours after endotoxin was injected into the rats．Results　MDA and O2　in endotoxemic rats liver mitochondria were significantly increased compared with normal group（P＜0.01)．Plasma MDA in experimental group was also significantly increased while GSH-Px and SOD were decreased compared with normal group（P＜0.01）．Although MDA and O2 of liver mitochondria in 912 group were lower than those in the others（P＜0.01)，SOD was not increased．Plasma MDA in 912 group was also significantly decreased 　while GSH-Px and SOD were increased compared with the others（P＜0.01)．Conclusion　Endotoxin which induces the increasing production of endogenous oxygen free radicals and lipid peroxidation plays an important role in the injury of rat liver mitochondria．Chinese Medicine，912，may prevent rat liver mitochondria damage through reducing O2－ and MDA．