The present study was undertaken to find a protective effect of Coptis Rhizoma Extract on liver injury induced by benzo(a)pyrene in rats. This crude drug significantly suppressed the increase of several biochemical parameters such as transaminase, lactate dehydrogenase and alkaline phosphatase in serum and liver and total cholesterol. But there were little changes in elevated serum phospholipid level. The results suggested that Coptis Rhizoma prevent bezo(a)pyrene-induced hepatic injury.