The experiment was conducted to evaluate the effects of medicinal plants on ethanol-metabolism. Sprague Dawley rats divided into 6 groups (n=8), fed with 10% ethanol and diets supplemented with each 1% of four plant extracts, ${alpha}-tocopherol$ (as positive control) and fiber (as negative control) for 4 weeks. Group supplemented with plant extract of Ulmus davidiana showed the most high value (322 nM NADH/min/mg protein) in alcohol dehydrogenase (ADH) activity among the experimented groups $(144{sim}312;nM;NADH/min/mg;protein)$ at p<0.05. Groups fed with Lagerstroemia indica and Zelkova serrata extract-supplemented diets indicated high activity in aldehyde dehydrogenase (ALDH, 16.7 & 12.3 M NADH/min/mg protein), which were comparatively lower than 20.1 M NADH/min/mg protein of ${alpha}-tocopherol$ fed group. All of the groups fed with plant extracts indicated very low GPT activities $(13.9{sim}17.3;IU/l)$ compared to those (146.1 & 128.6 IU/l) fed with ${alpha}-tocopherol$ and fiber at p<0.05. From these results, it is suggested that Lagerstroemia indica have a potent ethanol-metabolizing activity.