Abstract: Polyethylene glycol grafted epoxy resins (PEGF51) were prepared using α-methoxy-ω-N-isopropanol-para-phenylmethylamino polyethylene glycol (PO-p-MPEGBA) and novolac epoxy resin (F51). The structure of PEGF51 was characterized by infrared spectroscopy and gel permeation chromatography (GPC). Dynamic mechanical properties of PEGF51 cured with m-xylene-diamine (m-XDA) and novolac epoxy resin (F51) cured with PMAPEG were investigated considering polyethylene glycol segment molecular (M_PE) and bonding type as affecting factors. The results show that homogeneous polymers without nanophase separation are available by chemically incorporating poly(ethylene glycol) segments into epoxy resin networks. Damping properties of PEGF51/m-XDA (PEG segments were grafted on epoxy resin chains) were significantly improved. This PEG-grafted polymer exhibits great potential at M_PE=800, and the effective damping temperature is up to 52℃ for loss factor (tanδ)≥0.3.