Abstract: A molecularly imprinted solid phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry method was established for the determination of 14 kinds of nonsteroidal anti-inflammatory drugs in pork and liver. Sample was extracted twice by 10 mmol/L p H3.0 ammonium formate buffer, followed with defat by n-hexane.Supernatant was purified by molecularly imprinted solid phase extraction. Analytes were separated by BEH C18 column under gradient elution, then detected with mass spectrometry under positive and negative electric spray ionization and multiple reactions monitoring mode. The calibration curves of 14 nonsteroidal anti-inflammatory drugs were linear in the range of0.25⁵0 μg/L. The limits of detection and quantitation were 0.1 ~ 2 μg/kg and 0.25 ~ 5 μg/kg, respectively. In three different spike levels, the average recoveries in pork and liver were between 73.2% ~ 110.7%, with relative standard deviations of1.0% ⁹.7%. The sensitivity, precision and accuracy of this method were in accordance with the demand of veterinary residue determination, it is suitable for the multi residue determination of nonsteroidal anti-inflammatory drugs.