To develop an analytical method for determination of fipronil and chlorfenapyr residues in foodstuffs by gas chromatography-tandem mass spectrometry (GC-MS/MS).MethodsFipronil and chlorfenapyr were extracted with acetonitrile and cleaned-up by a PSA solid phase extract (SPE) column for GC-MS/MS determination. Fipronil and chlorfenapyr were separated by a THERMO TR-Pesticide II column and detected by multiple reaction monitoring (MRM) with electrospray ionization operating in the positive ion mode.Results The calibration curves were linear between the range of 5-50μg/L with r≥0.998. The recoveries of fipronil spiked sample ranged 78.2%-102.5% with RSD 6.8%-15.2%, and the recoveries of chlorfenapyr ranged 77.0%-104.1% with RSD 6.9%-17.1%. The limits of detection (LODs) and limits of quantification (LOQs) of fipronil and chlorfenapyr were both 5and 10μg/kg, respectively.Conclusion GC-MS/MS in positive ion mode is an simple, rapid, accurate analytical method for determination of fipronil and chlorfenapyr residues in foodstuffs