Abstract: A rapid method combining ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)with isotope dilution technique was developed for determining nine pesticide residues in tobacco. The analytes were extracted from tobacco samples by acetonitrile and purified by dispersion solid phase extraction with N-propyldiaminoethane as the sorbent, then qualitatively and quantitatively analyzed by a tandem mass spectrometer in multiple reaction monitoring (MRM) mode after being separated on BEH C₁₈ column. The pesticide residues were quantitatively analyzed with the corresponding deuteriums as the internal standards separately. The results showed that:1) Good linear relation was obtained in the range of 12.5-500 ng/mL for nine pesticides with r >0.998. 2) The limits of qualification and limits of quantification for nine pesticides were 0.003-0.009 and 0.011-0.030 mg/kg. The average standard recoveries obtained for control samples ranged from 85.5% to 110.1% with the relative standard deviations less than 6.0%. 3) After determining 30 real samples by this method, it was found that the results of the isotope internal standard method were in good agreement with that of the blank matrix matching standard calibration method, but the operation is simpler. This method has been applied for the analysis of nine pesticides in flue-cured tobacco, burley tobacco, oriental tobacco and tobacco products and found to be suitable.