It is a conventional point of view that berberine is poorly absorbed following oral administration. But in recent years berberine is orally used in clinical practice for the treatment of arrhythmia and congestive heart farlure. In order to solve the problem, this paper established a HPLC method (limit of quantification is 2?g ? L-1), to study the pharmacokinetic property of berberine in Beagle dogs. P-K curves of 100 mg intravenous injection is a two-compartment model with its K. 10. 18?h-1, T1/2?0. 15h, T 1/2?12. 59h, CL 60.70 L ? h-1,AUC 1979.31 ?g ? h-1 ? L-1and Vd 699. 53 L. Vomiting happened after 280 mg ? kg-1oral administrationgroup. Its T max is 3. 17 h, C max 15. 46?g?L-1, AUC 777. 29 Mg ? h-1 ? L-1, Vd 125. 41 L, Ke 0. 02?h-1and CL 2. 64 L ? h-1. The plasma concentrations after 45 mg ? kg-1 given orally are always below 10 mg v L-1. So are the concentration after 45 mg ? kg-1 orally given two times a day for one week. Severe Vomiting and diarrhea happened in all dogs of 700 mg ? kg-1 oral adminstration group,so the plasma concentration is below 1 0 ng ? L-1and its P-K parameters can't be determined.