Excess ethanol intake is usually toxic in health. Chronic ethanol consumption causes oxidative damage in liver. Alcohol dehydrogenase (ADH), microsomal ethanol oxidation system (MEOS) and catalase are related with the ethanol metabolism. Classical pathway of ethanol metabolism, which is catalysed by alcohol dehydrogenase to form acetaldehyde, results in the formation of free radicals. Acetaldehyde has been known to be a major contributor to hangover. Acetaldehyde is a malignant metabolite for vasodilation substance, flushing induction, and respiratory distress induction as well as exhibiting to be intense reactive and toxic. Acetaldehyde combined with phospholipid, amino acid residues, and sulfhydryl group may transform cell surface antigen andinduce lipid peroxidation and oxidant stress as well as depleting antioxidant enzyme glutathione (GSH). In this study, we investigated the effect of Acer tegmentosum MAX. extracts on relieving hangovers in rats. Male Sprague-Dawley rats were given Acer tegmentosum MAX. extracts (10ml/kg body weight) ingestion and before or after 40% Ethanol (5g/kg body weight) ingestion. The effect of Acer tegmentosum MAX. extracts on blood ethanol and acetaldehyde concentration was studied. In consequence, Acer tegmentosum MAX. extracts were recognized to reduce the blood ethanol and acetaldehyde concentration.