This study was performed to investigate the effects of green tea or antioxidant vitamins on lipid peroxidation and antioxidant enzyme system in various regions of rat brain aged 9 and 12 months. Male Sprague-Dawley rats were raised on the experimental diets; 3% green tea powder diet, antioxidant vitamins diet containing the $eta$-carotene, vitamin C, vitamin E in the level same as in the 3% green tea powder diet, and control diet far 3 weeks. We measured concentrations of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase, and glutathione peroxide (GSH-Px) in various brain regions such as cortex, cerebellum, striatum, and hippocampus. Green tea powder or antioxidant vitamin supplementation decreased MDA concentrations in the striatum and the hippocampus, and increased SOB activities in the striatum, and GSH-Px activities in the cortex. There was no significant difference in the observed antioxidative effects between the green tea powder and antioxidant vitamin supplementation. A significant difference between 9 month- and 12 month-old rats was found in MDA concentrations and GSH-Px activities in all brain regions. These results suggest that green tea powder can have protective effects on various regions of rat brain and that these effects on lipid peroxidation and antioxidant enzymes are different by age. In inhibiting lipid peroxidation, there was no difference between green tea powder and antioxidant vitamins.