A novel analytical method for simultaneous determination of xylazine and its metabolite 2，6-dimethylaniline（DMA） in pork was developed based on QuEChERS/liquid chromatography－tandem mass spectrometry（LC－MS/MS）. The analytical process was as follows： pork meat samples were homogenated for 1 min， followed by extraction with acetonitrile－2% acetic acid， cleanup with C,18,/PSA mixed adsorbent. The extracts were evaporated to dryness with high-purity nitrogen gas， and then dissolved in mobile phase A for LC－MS/MS analysis in positive ionization mode using multiple reaction monitoring（MRM）. The separation was carried out on a Waters C,18, separation column（100 mm × 2.1 mm， 3.5 μm） using 0.1% formic acid－water and 0.1% formic acid－acetonitrile as mobile phases. The effects of extraction solvents， types and amounts of adsorbents on the recoveries were investigated. Results showed that the effects of blank matrix on MS response of xylazine and DMA were checked， and the results showed weak suppression effects for xylazine（0.86） and DMA（0.89）. The quantitations of xylazine and DMA were completed by a matrix-matched external calibration method. The limits of detection for xylazine and DMA were 0.10 μg/kg and 0.30 μg/kg， and the limits of quantitation were 0.32 μg/kg and 1.00 μg/kg， respectively.Recoveries for xylazine and DMA were in the ranges of 95.6%－108% and 70.3%－79.5%， with their relative standard deviations（RSD） of 2.6%－2.8% and 3.1%－5.0%， respectively. To validate the developed method， ten pork samples collected from local supermarkets were determined. Xylazine was not detected in the ten samples except for one sample where 1.13 μg/kg of DMA was found. The present method is simple， rapid， sensitive and efficient， and is suitable for the detection of xylazine and DMA residues in pork.