Abstract: AIM　To develop a method for the determination of trimebutine maleate in rat plasma by using high performance capillary electrophoresis. The method was employed to pharmacokinetic analysis of trimebutine maleate. METHODS　Plasma samples were deproteinized with acetonitrile (containing ephedrine hydrochloride as internal standard) and the supernatant was dried under N₂ stream at 50℃. The residue was dissolved with methanol-water (1∶1) and injected into the capillary by siphon. The electrophoresis was performed in uncoated fused-silica capillary and the voltage was 10 kV. The running buffer was 0.03 mol·L^-1 NaH₂PO₄ (pH 6.0). The eluate was detected at 214 nm by UV detection. RESULTS　The recovery for trimebutine maleate in rat plasma was 72.8%-87.9%. The calibration curve in plasma was linear over the range 5-200 μg·L^-1. The limit of quantitation was 5 μg·L^-1. The intraday relative standard deviation (n=6) and the interday relative standard deviation (n=18) were less than 14%. The highest concentration in plasma was observed at 30 min after ig trimebutine maleate to rats. The pharmacokinetic results were AUC_0-∞=8 μg·min·mL^-1, T_1/2(Ke)=173 min and Ke=5.6×10^-3 min^-1. CONCLUSION　The method is accurate, sensitive and suitable for pharmacokinetic study of trimebutine maleate.