Three analytical methods were developed for the determination of hymexazol residues in 6 kinds of plant-derived agro-products(e.g.soybean，rice，cucumber，beetroot，cole and tomato) by gas chromatography with a flame photometric detector(GC-FPD)，gas chromatography with a nitrogen-phosphorus-detector(GC-NPD) and liquid chromatography tandem mass spectrometry(LC-MS/MS) ，respectively.In GC-FPD，samples were extracted with acetone-hexane.The extracts were derivated with dimethylthiophosphoryl(DECTP)，and then determined by GC-FPD，and quantified by the external standard method.In GC-NPD，samples were extracted with acetone-hexane.The extracts were purified with octadecylsilane(C18) sorbent，and then determined by GC-NPD，with quantitation by the external standard method.In LC-MS/MS，samples were extracted with acetonitrile.The extracts were purified with graphitized carbon black(GCB) sorbent，and then determined by LC-MS/MS with quantitation by the matrix matched calibrations.The calibration curves of three methods all showed good linearities，with correlation coefficients(r2) more than 0.998.At three spiked concentration levels，the inter day average recoveries of hymexazol were found to be in the range of 82%-96% for GC-FPD method with relative standard deviations(RSDs) of 34%-121%,81%-103% for GC-NPD method with RSDs of 4.1%-14.3% and 74%-110% for LC-MS/MS with RSDs of 2.5%-10.7%.In GC-FPD and GC-NPD，the limits of quantitation(LOQ) in beetroot were 0.05 mg/kg，and LOQs of other five matrices were 0.25 mg/kg.In LC-MS/MS，LOQs of 6 matrix were all 0.05 mg/kg.Three methods are accurate，and could meet the detection requirements of hymexazol residue in plant derived agro products.