Objective A ¹³C isotope labeled internal standard-gas chromatography-tandem mass spectrometric (GC-MS/MS) with dispersive solid phase extraction (d-SPE) method was developed for the simultaneous determination of 7 polybrominated diphenyl ethers(PBDEs)residues in milk. Methods After adding¹³C₁₂ isotope internal standard and extracted with 1% acetic acid acetonitrile,purified with the new Z-Sep+C18 dispersive agent, the analytes in the sample solutions were seperated by DB-5 column(30 m×0.25 mm,0.25 μm). Operated by electron impact ion source (EI) with multiple reactions monitoring (MRM) mode, the samples were analyzed by gas chromatography-tandem mass spectrometer.(GC-MS/MS). The quantifications were performed by the isotope internal standard method with matrix-matched calibration standards. Results Good linearity was obtained for 7 PBDEs in the concentration range of 0.500-100 ng/mL with correlation coefficients (r) above 0.999. Recoveries for 7 PBDEs at three spiked levels of 0.1,1.0, and 10 μg/kg were in the range of 89.7%-102.9% with relative standard deviations (RSDs,n=6) of 3.8%-8.3%. The limits of detection and the limits of quantification were in the ranges of 2.4-9.8 and 7.5-30 ng/kg, respectively.Conclusion The established method was simple, efficient and sensitive, and could be applied in the determination of 7 PBDEs in milk.