In order to evaluate the protective effects of extracts of Mori cortex radicis on carbon tetrachloride-induced hepatotoxicity, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactic dehydrogenase, malondiadehyde values and glutathione S-transferase activity were measured in ICR mice. The activities of serum aminotransferase and the hepatic content of lipid peroxide after carbon tetrachloride-treatment were markedly increased than normal control but those levels were significantly decreased by the treatment of butanol fraction of Mori cortex radicis mathanol extract. Glutathione S-transferase activity was decreased by carbon tetrachloride than control, but that also inhibited by the treatment of butanol fraction of Mori cortex radicis methanol extract. These results demonstrate a possible hepatoprotective role of extract role of extract of Mori cortex radicis against ${CCl_4}-induced$ hepatoxicity in vivo.