A new method was established for the determination of thiencarbazone methyl，isoxaflutole and their metabolites RPA203328 and RPA202248 residues in corn and soil by dispersive solid phase extraction（d-SPE） combined with ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.The samples were extracted with acidified acetonitrile（containing 1% formic acid），and acetonitrile phase was separated from sample solution through salting out phenomenon with sodium chloride.The acetonitrile solution was cleaned up by dispersive solid phase extraction.The analytes were determined by ultra performance liquid chromatography-tandem mass spectrometry.Factors affecting the extraction efficiency，such as type of extraction solvent，cleanup sorbent and instrumental condition，were investigated.The performance of this method was evaluated under the optimal conditions at the same time.The results indicated that the matrix effects of four target compounds in corn were more than 10%,and the matrix effects of the other three target compounds in soil were more than 10% except that for the RPA202248 was less than 10%.The calibration curves for all the analytes were linear in the range of 0.001-1.0 μg/mL with correlation coefficients of 0.994 5-0.999 5.The recoveries at spiked range of 0.005-0.1 mg/kg were in the range of 72.9%-116.5%，with relative standard deviations（n=5） of 0.75%-17.8%.The limits of quantitation were 0.005-0.01 mg/kg.With the advantage of quickness，high performance and environmental friendliness，the developed method is suitable for the determination of thiencarbazone methyl，isoxaflutole and their metabolites residues in corn and soil.