Abstract: An analytical method for the determination of 4 nitrofuran metabolites in pork has been developed based on the ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The metabolites in pork samples were hydrolized in hydrochloric acid, and derivatized with 2-nitrobenzaldehyde. After the extraction and concentration with ethyl acetate, the analytes were determined by UPLC-MS/MS in the multiple reaction monitoring mode using an internal standard method. Under the optimized conditions,all the analytes were in good linearity at the range of 0.5~50μg/kg and all the R² were greater than 0.995. The LODs for the metabolites were 0.2μg/kg and the LOQs were 0.5μg/kg.The average recoveries for the blank pork samples at three spiked levels(0.5,1.0 and 10.0μg/kg) ranged from 74.6% to 104.8%,with the relative standard deviations(RSDs, n=6) of 2.4%~15.6%.The proposed method is rapid, accurate and sensitive, and is suitable for the detection of nitrofuran metabolites in pork.