This study was conducted to investigate the effects of four kinds of tea (Camellia sinensis) extracts on the antioxidant defense systems as well as the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in ethanol administered ICR mice. According to the results, treatment with puerh tea significantly increased the superoxide dismutase activity and glutathion reductase activity in liver. In addition, the group treated with oolong tea exhibited higher superoxide dismutase activity and glutathion reductase activity in serum than those of puerh tea, green tea and black tea treated groups. The oolong tea and puerh tea also reduced malondealdehyde contents in both liver and serum. These results suggested that puerh tea and oolong tea were the most effective against alcohol-induced oxidative damage among the Camellia sinensis teas. On the other hand, in the measurement of alcohol break-down enzyme activities, the group treated with green tea exhibited the highest hepatic ADH and ALDH activities, suggesting that the group treated with green tea might be useful for alcohol down-regulation.