Abstract: Poly(ethylene glycol)(PEG)-modified epoxy resin(PEGE) was synthesized through an addition reaction, and the effect of synthetic parameters on epoxy value of PEGE was evaluated. Chemical structure of PEGE was characterized by Fourier-transform infrared spectroscopy and NMR spectroscopy, and its thermal stability, water solubility, particle size and surface tension were investigated. The results indicated that, for the synthesis of PEGE, the optimum mole ratio of PEG/epoxy resin was set as 1.6/1, the optimum reaction temperature was set to 120 ℃, the optimum reaction time was set as 2 h, and the amount of primary amine catalyst was set as 0.5 wt %. The PEGE exhibits a good application prospect due to its high thermal stability, good water solubility, high surface activity, small particle size and homogeneous distribution.