Abstract: A novel method based on the ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS) for the detection of perfluorooctane sulfonates (PFOS) in food packaging materials has been set up. The chromatographic conditions ware: the column used was ACQUITY UPLC BEH C₁₈（1.7 μm，2.1 mm×50 mm）；the temperature of column was 30 ℃;the mobile phase was acetonitrile/water, with gradient elution;the flow rate was 0.2 mL/min. PFOS was detectable using the electrospray ionization(ESI) on a tandem mass spectrometer in a multiple reaction monitoring mode. Qualitative analysis of PFOS was performed using the relative abundance of two daughter ions of PFOS, and quantitative analysis was conducted with the external standard method. The linear calibration curve was obtained in the range of 0.005～0.500 μg/mL with a linear correlation coefficient (R²) of 0.999. The recoveries for PFOS were 90.0%～101.6% with relative standard deviations of 1.5%～3.5%. And the detection limit for PFOS was 0.1 μg/m² (S/N≥3).