This study was to investigate the effect of dietary protein and fiber on the antioxidant enzyme activities of brain in acute or chronic ethanol-treated rats. Male Sprague-Dawley rats were fed on diets containing two levels of protein(7%, 20%) with two levels of fiber (5%, 10%) Rats were administered 40%(v/v) ethanol(5g/kg body weight)orally 90min before decaptiation in acute ethanol-treated groups and 25%(v/v) ethanol(5g/kg body weight) once a day for 5 weeks in chronic ethanol treated-groups. The rats were sacrificed after 5 weeks of feeding periods. Superoxide dismutase and gluthathione S-transferase activities were lower in chronic ethanol-treated groups than acute ethanol-treated groups whereas catalase and glutathuone peroxidase activities were significantly increased by chronic ethanol treatment. Low protein supplement accelerated to change of their activities however dietary fiber levels did not affect antioxidant enzyme activities. Chronic ethanol treatment and/or low protein supplement results in increasing the brain lipid peroxide content but in lowering glutathione level. (Korean J Nutrition 33(6) ; 613~618, 2000)