A method based on ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）with gel permeation chromatography was developed for the quantitative analysis of 16 kinds of oil-soluble synthetic dyes in feeds.The conditions of sample preparation and analysis were optimized in this thesis.The dyes were firstly extracted with 20 mL of ethyl acetate-cyclohexane（1∶1），and 5 mL of the extract was injected into the gel permeation chromatography（GPC）cleanup system.The elution was performed with a mixture of ethyl acetate-cyclohexane（1∶1） at a flow rate of 5 mL/min.The elution fraction in 15.8-48.3 min was collected.A UPLC separation was carried on a BEH Ｃ18 column（1.0 mm×100 mm，1.7 μm）by gradient elution using methanol -0.1% formic acid as mobile phase at a flow rate of 0.3 mL/min16 kinds of dyes were detected under positive electrospray ionization（ESI）.The method was quantified by the external standard method and the linear ranges for 16 kinds of dyes were in the range of 2-100 μg/L with correlation coefficients greater than 0.99.The average recoveries for 16 kinds of dyes in feeds ranged from 66.4% to 108.5% at three different levels.The limits of detection were 25 μg/kg and the limits of quantitation were 50 μg/kg.The results indicated that the method developed was highly sensitive and selective in determination of 16 kinds of oil-soluble synthetic dyes in feeds.