A high performance liquid chromatography-tandem mass spectrometric（HPLC-MS/MS） method was developed for the determination of tralomethrin residues in ten kinds of plant-based foods,including vegetables,fruits,tea and bean.The samples were extracted with ethyl acetate for vegetables,fruits,tea,and acetonitrile for bean.The extract was concentrated and purified by solid phase extraction（SPE）.Chromatographic separation was achieved by HPLC on an Agilent ZORBAX Eclipse XDB C18 chromatographic column using methanol-0.1% formic acid with 10 mmol/L ammonium acetate as mobile phase by gradient elution.The detection was performed by tandem mass spectrometry under multiple reaction monitoring mode and the quantification by the matrix-matched external standard method.Results showed that the calibration curve of tralomethrin was linear in the range of 20-1 000 μg/L with a correlation coefficient of 0.999 8.The recoveries for tralomethrin at three spiked levels（0.01,0.02,0.1 mg/kg for cereals,teas and beans and 0.005,0.01,0.05 mg/kg for fruits and vegetables） were between 75% and 92% with relative standard deviations（RSDs,n=6） of 4.0%-126%.The limits of quantitation（S/N≥ 10） were 0.01 mg/kg for cereals,teas and beans,and 0.005 mg/kg for fruits and vegetables.The method can be used to separate and identify deltamethrin and two diastereoisomers of tralomethrin while the gas chromatography（GC） with electron capture detector（ECD） and MS detector,which are routinely applied in the analysis of pyrethroid pesticides in foods,but cannot distinguish these two pesticides.