Puerariae Radix is one of the medicinal plants used in oriental medicine for hangover, It has been claimed for several pharmacological effects including anti-alcohol abuse, antidipsotropic activity and anti-alcohol intoxication. In connection with Puerariae Radix effects, an activity-guided purification of active substance on alcohol dehydrogenase (hnH) was carried-out. The most active compound was isolated as puerarin (C$_{21}$H$_{20}$ O$_{9}$ ), molecular weight 416. Puerarin inhibited ADH noncompetitively against ethanol or NAD$^{+}$./.