Abstract: The 2.00 g of homogenized pork was taken, and 20 μL of 1.0 mg·L⁻¹ mixed internal standard solution was added. After mixing well, the mixture was settled for 10 min. A ceramic homogenizer was added, the mixture was mixed thoroughly, and 6.0 mL of acetonitrile solution containing 0.1% （volume fraction, the same below） formic acid was added. The mixture was mixed by vortex, and sonicated for 5 min. An extraction salt package consisting of 4.0 g of sodium sulfate and 1.0 g of sodium chloride was added, and the mixture was shaken for 3 min, and centrifuged at 4 ℃ for 10 min. Then, the supernatant was collected, 4.0 mL of acetonitrile solution containing 5% （volume fraction） formic acid was added into the residue, and the extraction was repeated once following the same procedure. The two extracts were combined, mixed well, and centrifuged at 4 ℃ for 10 min. The entire supernatant was passed through a Captiva EMR-Lipid solid phase extraction column. The eluate was controlled to flow out at the rate of 2–3 drops·s⁻¹ under atmospheric pressure, and the solid phase extraction column was emptied by applying vacuum at the end of the elution. All the eluate was collected, and evaporated to near dryness with nitrogen at 40 ℃. The mixed solution （1.0 mL） of acetonitrile and 0.1% formic acid solution at volume ratio of 1∶9 was added, the mixed solution was vortexed for 1 min, and passed through a 0.22 μm filter. The analytes in the filtrate were determined according to the high performance liquid chromatography-tandem mass spectrometry. The target compounds were separated on the Agilent Poroshell 120 EC-C₁₈ chromatographic column using the mobile phase system of 0.1% formic acid solution and acetonitrile solution containing 0.1% formic acid （positive ion mode） or the water-acetonitrile system （negative ion mode）, detected using the electrospray ion source in positive and negative ion modes with multiple reaction monitoring mode, and quantified by the internal/external standard method. It was shown that linear relationships between the mass concentrations of the 37 veterinary drugs and peak areas of the quantitative ion or the peak area ratios of quantitative ions of target compounds to internal standards were kept in the range of 2‒100 μg·L⁻¹, with detection limits in the range of 0.05–2.0 μg·kg⁻¹. Test for recovery was performed using the standard addition method, giving recoveries in the range of 63.2%–106%, and RSDs （n=6） of the determined values ranged from 2.7% to 7.9%.