Abstract: An analytical method has been developed to determine simultaneously plasma concentration of the enantiomers of verapamil and its major metabolite, norverapamil, using capillary zone electrophoresis. Trimethyl-β-cyclodextrin was selected as chiral selector. Good separation was achieved under the conditions as below: Running electrolyte was pH 2.5, 60 mmol·L^-1 phosphate buffer containing 60 mmol·L^-1 trimethyl-β-cyclodextrin; capillary: 30 cm×75 μm(ID), coated; setpoint of capillary temperature: 20℃; detector: UV 200 nm; injection: electromigration at 12 kV for 7 s; running voltage: 14 kV. Solvent of sample was doubly deionized water. The migration times of enantiomers were less than 12 min. The good linear range was from 300.0 ng·ml^-1 to 2.50 ng·ml^-1. Relative standard deviations of assay accuracy and precision were less than 12%. It fits for routine therapeutic monitoring as it is highly efficient, rapid, sensitive, with less solvent and sample consumption and automation.