The method is based on the oxidation of chlorpromazine with ammonium metavanadate in pH 2. 4 solution, the absorbance of coloured compound was measured at 530nm. Calibration graphs are linear over the concentration range 0~250g/mL. The apparent molar absorptivity was 1.28X103L·mol-1·cm-1. The proposed method was applied to the determination of chlorpromazine tablets with satisfactory results. The solution is based on the oxidation of chlorpromazine with ammonium metavanadate in pH 2. 4 solution, the absorbance of the colored compound was measured at 530 nm. Calibration graphs are linear over the concentration range 0-250 g / mL. The apparent molar absorptivity was 1.28 × 103 L · Mol -1 · cm -1. The proposed method was applied to the determination of chlorpromazine tablets with satisfactory results.