To establish a method for the determination of chlorphenamine maleate in chlorphenamine maleate tablet by large volume injection-acetonitrile salt stacking-MEKC.The determination conditions containing concentrations of acetonitrile and sodium chloride in sample matrix on separation efficiency were optimized.The result indicated that a best separation of chlorphenamine maleate was obtained on an uncoated fused silica capillary column (50 cm×50 μm,effective length 36 cm） by using the background electrolyte containing 12 mmol/L sodium tetraborate,50 mmol/L boric acid and 50 mmol/L SDS,and 10% methanol at pH 9.1 ,70% acetonitrile-200 mmol/L sodium chloride(NaCl）in standard and sample matrix at 25 ℃. The detection wavelength was set at 215 nm,sample injection voltage was 20 kV and injection time was 120 s. Under the optimum conditions,chlorphenamine maleate was separated in 14 min with theoretical plate number of 677 240.The relative standard deviations(RSDs） for peak area were less than 4%. The calibration curve was linear in the range of 0.398-6.368 mg/L for chlorphenamine maleate with a detection limit (S/N=3） of 8.95 μg/L. The spiked recoveries were in the range of 93%-102%.Compared with that of the normal MEKC method detection limit (82.3 μg/L）,the sensitivity of the proposed method was increased by 10 times.