Ethanol concentration in blood, brain and liver of rats was shown to be effectively lowered by arrowroot flower extract. The lowering effect for ethanol concentration in blood was maximum when measured after 1 hour from ethanol feeding. Hot water extract was more effective than 80% ethanol extract. The treatment of extract at 10 min. before ethanol feeding gave a better result than that at 10 min after or 1 hour before ethanol feeding. The ethanol concentration in brain and liver was lowered as found in the blood ethanol concentration. Acetaldehyde was not detected either in blood or the tissues. The optimal amount of the Puerariae flos was 55.7㎎/㎏·body weight. The newly developed analytical method using dichloromethane as extracting solvent was proven to be very effective in terms of speed and simplicity.