Abstract: A method of capillary zone electrophoresis was developed for the determination of ftoafur,gimeracil and potassium oxonate in Tijiao capsules. An elastic quartz capillary tube was used for separation at 20 ℃ and the separate voltage of 30 kV with a running buffer of Na2HPO4 (2 mmol·L-1,pH=11.8). The detection wavelength was 220 nm. The linearity ranges of ftoafur and passium oxonateot were 50-500 mg·L-1 and the linearity range of gimeracil was 14.5-145 mg·L-1. The detection limits were 1.0,2.3,0.6 μg·L-1,respectively. The recovery rates measured by standard addition method were in the range of 98.2%-100%,and RSD (n=9) were in the range of 0.4%-0.9%.The method was used for analyzing Tijiao capsules,giving results in agreement with the indicated value.