Abstract: AIM　To study the pharmacokinetics of epristeride(EPR) in rats and Beagle dogs. METHODS　The concentrations of EPR in biological samples were determined by an HPLC method with UV detection. RESULTS　The concentration-time curves in rat serum showed two peak concentrations after ig doses of 10, 20 and 40 mg.kg^-1. The T_peak1 and T_peak2 were attained within 0.5～1 h and 3～4 h, respectively. The elimination half-life(T1/2β) was 2.43～3.14 h. The T_peak and T_1/2β in Beagle dogs were 1 h and 5 h, respectively. EPR was shown to be widely distributed to various tissues after ig dose of 20 mg.kg^-1. The concentrations in most tissues at 3 h were higher than those of 6 h. The excretion of parent drug in urine amounted to only 0.09% of the dosage and in feces to 42.9% within 24 h after dosing. The biliary excretion were mainly metabolites and only 0.14% of parent drug of the dosage within 12 h. Plasma protein binding ratio of EPR was 92.3% at the concentration range of 50～3 000 ng.mL^-1. CONCLUSION　The absorption of EPR was shown to be of first order processes at doses of 10～ 40 mg.kg^-1, both the C_max and AUC increased proportionally with the dosages. EPR was shown to be widely distributed to the various tissues and mainly eliminated via the feces and bile.