Abstract: For the purpose of rapid screening of hypocholesterolemic agents, we applied the Wybenga's method with slight modification to determine the serum cholesterol level of normal male rats. We did a series of experiments. Results showed that the cholesterol level of rats presented a pattern of normal distribution. Weekly blood-sampling or daily stomach-intubation had no influence on the cholesterol level. Thus we considered that normal male rats could be employed as an animal model for screening hypocholesterolemic drugs. Thereafter, we used the method to test the hypocholesterolemic effect of heshouwu(Polygonum multiflorum Thunb.), scale-oil of hairtail(Trichiurus chinensis) and"compound phosphoesterase tablets". The data showed that heshouwu and scale-oil of hairtail were both effective, they lowered the serum cholesterol by 20 per cent, which was considered as the critical value of effectiveness, but"compound phosphoesterase tablets" did not show any effect at all.