Abstract:A method was established to determine the acetamiprid residues in garlic by stir bar sorptive extraction combining with liquid chromatography-mass spectrometry method.The sample was extracted by SBSE.After being desorbed，the sample was performed on Hypersil GOLD-1.9 μm，50 mm×2.1 mm（i.d）column.The analysis was carried out in the selected reaction monitoring and external standard method was used for quantification.The calibration curve of the acetamiprid was good linear from 0.005 mg/L to 0.2 mg/L with the correlation coefficient r=0.999 8，the detection limit of this method was 0.005 mg/kg.In different concentrations，the average recoveries of this method were 82.3%-92.2%and the variability coefficient were 7.73%-9.01%.The method is easy，rapid，and can be applied to the determination of acetamiprid in garlic.