A sensitive high performance liquid chromatographic analytical method was established for determining the concentration of matrine in human serum. The recovery of matrine was 99.1-102.2%. The RSD (%) in within-day and between-days were no more than 6%. The calibration curve was linear in the range from 1.25 micrograms.ml-1 to 40.0 micrograms.ml-1 with r = 0.9997. The serum drug concentration-time curve after iv infusion with a dose of 6 mg.kg-1 in 100 ml glucose solution for 8 healthy volunteers was fitted to a 2-compartment open model. The excretion of unchanged drug in urine was 52.75% of the dose in 32 h and the ClR was 143.79 ml.min-1.