Abstract: An ultra performance liquid chromatography coulped to tandem mass spectrometry (UPLC-MS/MS) method was established for the determination of trimethoprim, clindymycin, tiamulin and praziquantel residues in animal origin food. The sample was extracted with acetonitrile, purified by hexane, and detected on Waters Acquity UPLC BEH C18 column by a gradient elution using acetonitrile (A) —0.1% formic acid (B) as mobile phase with a flow rate of 0.3mL/min. The calibration curves were good linear between the peak areas and concentrations of 4 veterinaries in the range of 2.5～200μg/L, with correlation coefficients more than 0.996. The average recoveries at this concentration levels ranged from 65.8% to 95.9%, the RSD was in the range of 3.2%¹3.1%.The limits of quantification of 4 drugs in animal origin food were 0.5μg/kg.