The anti-oxidant activities of tectochrysin, a major compound of propolis, were investigated. Tectochrysin exhibited a significant decrease in serum transaminase activities elevated by hepatic damage induced by CCl4-intoxication in rats. Tectochrysin tested exhibited a lipid peroxidation causing a significant decrease in MDA production in TBA-reactant assay. Tectochrysin was strong in the increase in the anti-oxidant enzymes such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase activities in CCl4-intoxicated rats. These results suggest that tectochrysin possess not only the anti-oxidant, but also the activities in CCl4-intoxicated rats. Especially, tectochrysin was found to cause significant increases in the rat liver cytosolic SOD, catalase, GSH-px activities as well as a significant decrease in the MDA production.