The present study was undertaken to investigate the possible effect of ginseng butanol fraction on the hepatic acetaldehyde metabolism. Experimental animals were used for the subject of the study. When, in case of mitochondrial aldehyde dehydrogenase (Ald DH), ginseng butanol fraction was added, enzyme activity was increased in a small dose, while, in a large dose, it showed inhibitory effect. In terms of kinetic aspect, ginseng butanol fraction has the effect to decrease the Km values of Ald DH. In vivo studies, the activity of Aid DH increased by induction of acute intoxication of ethanol was further increased through pretreatment with ginseng butanol fraction. When ginseng butanol fraction was given to mice fed with 5% ethanol instead of water for 60 days, the activity of Ald DH in mitochondrial fraction decreased to about 35% in chronic alcoholism, but after pretreatment of ginseng butanol fraction the activity was restored to the control level. By the pretreatment with disulfiram, the Ald DH activity was inhibited in normal and alcohol-treated groups, but after the treatment with ginseng butanol fraction the activity was restored to the control level. The results suggest that ginseng butanol fraction enhance the Ald DH activity inhibited by the treatment of disulfiram with no relation to NAD. It was observed that ginseng butanol fraction markedly decrease the acetaldehyde levels in plasma and liver. All these observations suggested that reduction of acetaldehyde in blood and liver should be dependent upon increased activity of mitochonclrial Ald DH. It is concluded that the recovery from alcohol intoxication should be prompted by treatment with ginseng.