Abstract: AIM To develop a nonaqueous capillary electrophoresis method for simultaneous determination of six antipsychotic drugs. METHODS The separation was performed on a fused silica capillary of 75μm ID×57 cm (50 cm of effect length), the running buffer was methanol acetonitrile (75∶25) containing 150 mmol·L^-1 ammonium acetate and 1.0% glacial acetic acid. Samples were solved in the buffer containing 15 mmol·L^-1 ammonium acetate and injected by pressure mode. The applied voltage was 20 kV and the detection wavelength was set at 254 nm. RESULTS The method was validated in terms of reproducibility, linearity (γ>0.999 for all analytes), limits of quatitation and detection. The paper also discussed the buffer composition, applied voltage and temperature which influenced the separation. CONCLUSION The nonaqueous capillary electrophoresis method is effective, simple, fast and reliable. The six antipsychotic drugs which have similar structrure can be separated by this method at the same time, but only five of them can be separated by capillary zone electrophoresis which was based on the aqueous buffer. At the same concentration of buffer in nonaqueous capillary electrophoresis and capillary zone electrophoresis, the former would acquire much lower current and less Joule heat.