A determination method of fipronil and its metabolites (fipronil desulfinyl,fipronil sulfide and fipronil sulfone) in liver tissue of Cyprinus carpio was developed by quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction coupled with high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted with 0.1% formic acid acetonitrile, and purified by neutral alumina, PSA and GCB. Then, fipronil and its metabolites were detected by using LC-MS/MS. The analytes were quantified with external standard using the matrix-matched standard calibration curve method. The results showed that the average spiked recoveries of fiproni and its metabolites in liver tissue of fish were 87.3%~109.2%with relative standard deviations(RSDs) of 1.3%~12.0%. Good linearities were obtained in the range of 0.4~100.0 ng/mL, and the correlation coefficients were greater than 0.997, the LODs were 2.0 μg/kg, and the LOQs were 5.0 μg/kg. The method was simple, rapid and sensitive. And the preparation for a single sample was within 20min. The developed method is suitable for studying the metabolism and residue elimination of fipronil in fish liver. [Chinese Fishery Quality and Standards,2021,11(2):18-24]