A sensitive solid phase extraction/high performance liquid chromatography-tandem mass spectrometric（SPE/HPLC-MS/MS） method was developed for the determination of kasugamycin residues in cucumber and soil.The cucumber and soil samples were extracted with 1% formic acid methanol solution and 0.5% formic acid water solution,respectively,and cleaned up with MCX solid phase extraction column,then separated on a Waters Xbridge BEH Amide column using acetonitrile-0.2% formic acid as mobile phase by gradient elution.The qualitative and quantitative analyses were performed under positive electrospray ionization（ESI+） in multiple reaction monitoring（MRM） mode,with the matrix matched calibrations.The calibration curves showed good linearities in the concentration range of 2-250 μg/L with correlation coefficients more than 0.999.The limits of detection（LOD） and the limits of quantitation（LOQs） were 0.002 mg/kg and 0.008 mg/kg,respectively.The average recoveries at four spiked levels（0.008,0.040,0.200,0.400 mg/kg） were in the range of 77.5%-97.0% for cucumber and soil,with relative standard deviations（RSDs） of 2.6%-10.7%.The method is simple,rapid,sensitive,accurate and reproducible,and could meet the requirements for analysis of kasugamycin residues in cucumber and soil samples.The method was applied in the detection of the field samples,and the contents of kasugamycin residues in cucumber and soil were found not more than 0.053 mg/kg and 0.013 mg/kg,respectively,which were below the maximum residue limits（MRL） for kasugamycin in cucumbers defined by China（0.2 mg/kg）.