Excessive or long term ingestion of alcohol may cause hepatitis, cirrhosis, hepatic tumor and so on. Aldehyde and active form of free oxygen that are metabolites of alcohol in liver are the cause of liver cell damage. The main system of alcohol metabolism is composed of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and cytochrome P450. In connection with in vivo alcohol metabolism, more than one hundred natural products were screened for inhibition or activation of alcohol dehydrogenase. As a results, we found significant inhibition ($IC_50$) of ADH by methanolic extracts of Puerariae Radix ($61.2{;}mu extrm{g}/ml$), Glycyrrhizae Radix ($105.0{;}mu extrm{g}/ml$), Cinnamomi Ramulus ($7.0{;}mu extrm{g}/ml$), Rhei Rhizoma ($36.7{;}mu extrm{g}/ml$), Mori Cortex Radicis ($106.2{;}mu extrm{g}/ml$), Chrysanthemi Flos ($112.2{;}mu extrm{g}/ml$), Erycibes Caulis ($36.7{;}mu extrm{g}/ml$), and Scutellariae Radix ($122.5{;}mu extrm{g}/ml$)