The purpose of this study was to investigate the preventive effects of Lycii fructus Extract (LFE) against the acute hepatotoxicity-inducing lipopolysaccharide (LPS) in the liver. LFE of 100 mg/kg concentration was intraperitoneally administered into rats at dose of 1.5 ml/kg for 20 days. On the day 21, 1.5 ml/kg of LPS dissolved in saline was injected 4 hours before anesthetization. We examined the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), lactate dehydrogenase (LDH) in serum of rats, superoxide dismutase (SOD) in mitochondrial fraction, and malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPx) in liver homogenate. LPS-treatment markedly increased the levels of GOT, GPT, LDH and MDA, and significantly decreased those of SOD, CAT and GPx. But LFE-pretreatment decreased the levels of GOT, GPT, LDH and MDA, by 17.7%, 27.5%, 40.7% and 56.9%, respectively and increased those of SOD, CAT and GPx, by 90.5%, 78.9% and 83.8%, respectively. These results showed that the LFE had the preventive effects against the acute hepatotoxicity-inducing LPS in the liver.