Abstract: A method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous determination of three high risk pyrrolidone pesticide adjuvants in emulsifiable concentrate (EC) and soluble concentrate (SL) pesticide formulations. After diluting with methanol, the pesticide formulation was centrifuged at 8 000 r/min for 5 min at 20 ℃, and the supernatant was filtered through 0.22 μm membrane. After separation on a VF-WAXms column, the analytes were detected by GC-MS/MS at multiple reaction monitoring （MRM） mode and quantified using the external standard method. Good linearities were obtained for the three pyrrolidone pesticide adjuvants in the linear range of 1.0-40.0 mg/L with the correlation coefficients （R²） larger than 0.999. The limits of quantitation (LOQs) were 3.1-6.8 mg/kg. The average recoveries in EC and SL samples were 98.2%-108.9% and 98.1%-111.7%, and the relative standard deviations （RSDs, n=6） were 0.4%-2.6% and 0.4%-3.4%, respectively. 94 samples of EC and 27 samples of SL-pesticide formulations sold in the market were detected. N-methyl pyrrolidone was detected in 6 samples with the contents ranging from 0.022% to 11.328%, and 2-pyrrolidone was detected in 2 samples with the contents ranging from 0.018% to 0.023%. This method has certain advantageous, such as simpler operation, higher sensitivity, and better accuracy, which is suitable for the simultaneous determination of three pyrrolidone pesticide adjuvants in EC and SL pesticide formulations.