A simple high-performance liquid chromatography methodology was developed to study the pharmacokinetics of paeonol in the rat after intravenous (iv) bolus administration of various doses (2.5, 5, or 10 mg/kg). The pharmacokinetics of paeonol in rat plasma at each dose were well described by a two-compartment model. The area under the curve increased proportionally with dose and consequently total body clearance was independent of dose. There was no dose-related difference in the elimination half-life or volume of distribution. These results indicate that the pharmacokinetics of paeonol after iv administration are linear over the 2.5-10 mg/kg dose range.