Perfluorooctane sulfonate (PFOS) has been found globally as an environmental contaminant and identified as persistent,bioaccumulative and potentially toxic compound in exposed biota including humans[1].In this paper,a quantitative method was developed for measuring PFOS in textiles.The ultrasonic-microwave synergistic extraction was chosen as the best extracting method,and then sample extracts were cleaned up successively with the solvent CH2Cl2.Triethylorthoacetate (TEOA) was used for derivatization and PFOS was converted to corresponding sulfonic ester,which could be identified and quantified by gas chromatography with mass spectrometry.A methyl/phenyl mixed-phase fused-silica capillary column was used for gas chromatographic (GC) analyses.Mass (MS) spectra were generated using electron ionization (EI) mode.