An analytical method was developed for the simultaneous detection of flupyradifurone and its three metabolites ie.difluoroacetic acid（DFA），6-chloronicotinic acid（6-CNA） and difluoroethylaminofuranone（DFEA） in citruses by ultrahigh performance liquid chromatography tandem mass spectrometry（UPLC-MS/MS）.Citrus samples were extracted with acetonitrile，and cleaned up by dispersive solid phase extraction（PSA）.The analytes were detected in multiple reaction monitoring（MRM） mode under alternate positive/negative electrospray ionization（ESI+/ESI- ） mode，and quantified by the external standard method.The results showed that there were good linearities for flupyradifurone and its metabolites in their respective concentration ranges with correlation coefficients of 0.997 9-0.999 6.The limits of detection were 0.001 mg/L.The average recoveries for the analytes in the whole citrus fruit and fruit pulp at spiked levels of 0.05，0.3 and 2 mg/kg ranged from 71.9%to 106%with relative standard deviations（RSDs） of 0.8%-9.1%.The average recoveries of the analytes in citrus fruit peel at spiked levels of 0.1，0.3 and 3 mg/kg ranged from 77.9%to 100%with relative standard deviations（RSDs） of 1.2%-6.5%.The limits of quantitation（LOQs） for flupyradifurone and its metabolites in the whole citrus fruit，fruit pulp and peel were 0.05，0.05 and 0.1 mg/kg，respectively.The method is simple，stable，rapid and sensitive，and is suitable for the determination of flupyradifurone and its metabolites in citrus samples.