Abstract: A method of headspace-gas chromatography-mass spectrometry (HS-GC-MS) was proposed for the determination of 3 foaming agents, i.e. HCFC-22, CFC-11 and HCFC-141b in combined polyether polyols. The sample was dissolved in methanol, and placed in the HS-flask with adding 0.1 mL of 2 000 mg·L^-1 monobromochloromethane solution as internal standard. The mixture was extracted by headspace oscillation for 10 min at the temperature of 60℃. GS-GasPro chromatographic column (60 m×0.32 mm) was used for the separation, and full scan mode was adopted in the determination. Linearity ranges of HCFC-22, CFC-11 and HCFC-141b were found in the same range of 5-100 μg, with their detection limits (3.143s) of 0.2 μg·g^-1. The proposed method was applied to the analysis of samples of combined polyether polyols, and values of recovery found by standard addition method were ranged from 82.0% to 106%, with RSDs (n=6) in the range of 2.5%-11%.