Objective To establish a method for simultaneously determining the concentration of clozapine and amisulpride in human plasma by HPLC.Methods The drugs from plasma was analyzed in a reverse phase HPLC system ZE Month Crest DDS-L column (4.6 mm × 250 mm,5 μm); mobile phase consisted of 30 mmol? L-1 postassium dihydeogen phosphate ( pH 7.5) -methanol (35∶65);the flow rate was 1.0 mL? min-1 and the column temperature was 35 ℃; the detection wavelength was at 270 nm.Ether was used as extracting solvent.And then the specificity, lower limit of quantitation and standard curve, precision and recovery rate and stability of the method were investigated. Results The calibration curves were linear in the range of 10 -1000 ng? mL-1 for clozapine, the regression equation of clozapine was Y=4.20 ×10 -3 C -3.13 ×10 -2 (r=0.999 4).The relative recovery rate ranged from 91.89% to 95.18% and the absolute recovery rate ranged from 93.78%to 107.70%.The calibration curves were linear in the range of 10-1000 ng? mL-1 for amisulpride, the regression equa-tion of amisulpride was Y=3.60 ×10 -3 C-3.12 ×10 -2 ( r=0.999 2 ) . The relative recovery rate ranged from 92.98%to 95.51%and the abso-lute recovery rate ranged from 91.50%to 96.54%.The intra-day and inter-day variation ( RSD) were both lower than 15%.Conclusion The method is sensitive, accurate, simple and quick, it can be used for clinical drug monitoring and pharmacokinetics studies of clozapine and amisulpride.