OBJECTIVE：To study the effects of virus in activation treatment of plasma specimen on plasma concentration determination of voriconzole ，linezolid，vancomycin and teicoplanin. METHODS ：The remaining plasma of 36 inpatients in our hospital after routine blood concentration examination of voriconazole ，linezolid，vancomycin and teicoplanin were collected as specimen（9 drug-contained plasma specimens for each drug ），and merged into three different concentration levels （low，medium， high）of mixed samples according the results of routine blood test. Then the mixed samples with different concentration levels were divided into inactivated group and non-inactivated group ，with 3 samples in each group. The inactivated plasma samples were heated at 56 ℃ for 30 min in metal bath with constant temperature. Non-inactivated group were not treated. After pretreating plasma sample of 2 groups，2-dimensional liquid chromatography was used to detect plasma concentration of the four drugs ；the difference of detection result between inactivated group and non-inactivated group were analyzed. RESULTS ：Plasma samples containing voriconazole，linezolid，vancomycin and teicoplanin were still stable after heating at 56 ℃ for 30 min in metal bath with constant temperature. Compared with non-inactivated group ，relative error of plasma concentration detection result of above 4 drugs were all lower than 15％ in low ，medium，high concentration mixed samples of inactivated group. CONCLUSIONS ：Plasma samples can be inactivated by heating at 56 ℃ for 30 min in metal bath with constant temperature ，when the plasma concentration of voriconazole，linezolid，vancomycin and teicoplanin are determined by 2-dimensional liquid chromatography.