Abstract: A high performance liquid chromatography-tandem mass spectrometric method with modified QuEChERS method for sample preparation was developed for the simultaneous determination of 10 chemical drugs added illegally in herbal tea. The samples were extracted with acetonitrile,purified with QuEChERS method and filtrated by 0.22 μm microporous filters. The separation was carried on an Agilent SB-C18 Column(100 mm×4.6 mm,2.7 μm)by a gradient elution using acetonitrile-0.01 mol/L ammonium acetate solution(contain 0.1% formic acid aqueous)as mobile phase. The analytes were detected by tandem mass spectrometry under multiple reaction monitoring(MRM)mode with positive electrospray ionization(ESI⁺)and quantified by external standard calibration method. The correlation coefficients of the standard calibration curves for the 10 analytes were all above 0.9984.The limits of detection was 0.1~3.0 μg/L. The blank samples were fortified at three levels,and the average recoveries ranged from 67.1% to 108.5% with the RSDs from 0.2% to 6.9%. The method developed was easy to operate,sensitive,and had good purification effect. It could be applied for the rapid determination of ten chemical drugs added illegally for the treatment of cough and asthma in herbal tea.