OBJECTIVE　To establish an assay for the simultaneous determination of propofol and lidocaine in human plasma using reversed-phase high performance liquid chromatography（RP-HPLC）.METHODS　With thymol and bupivacaine as the internal standards for propofol and lidocaine respectively,the extraction was performed with cyclohexane.The organic layer was evaporated and the residue was redissolved by mobile phase.The concentrations of propofol and lidocaine were assayed on a hypersil BDS C18 column with a mobile phase consisting of acetonitrile-methanol-water（10∶60∶30）（including 0.14% n-butyamine 0.1% acetic acid）at a flow rate of 1 mL*min-1 and detected at 220 nm during 1～7 min and at 273 nm during 7～16 min.RESULTS　The linearity between concentrations and peak area ratio was obtained from 0.1 μg*mL-1 to 25.6 μg*mL-1（r=0.998，r=0.9995）.The detection limits were 0.1 μg*mL-1 for propofol and 0.05 μg*mL-1 for lidocaine.The within-day and between-day variation coefficients were less than 5%(n=5).The average recoveries were 93.33%,99.4% and 90%,95.67% respectively.CONCLUSION　The method was found to be rapid,accurate and precise.It is suitable for clinical pharmacokinetic and pharmacodynamic study.