EP/SiO2 hybrid materials, which contained flexible chain, were prepared by epoxy resin (EP) and polyethylene glycol (PEG)-grafted polysilicic acid (PSA), which was obtained by endcapping polyethylene glycol-1000 with toluene 2,4-diisocyanate (TDI), followed by a reaction with polysilicic acid. The formation of hybrid materials was confirmed by a wide-angle X-ray diffraction (WAXD) and atomic force microscopy (AFM) analysis. Results showed that the EP/SiO2 hybrid particles were nanosized and the average size was about 20-50 nm. The mechanical properties, dynamic mechanical properties, and thermal properties were evaluated and compared with the corresponding matrix. The improvement in impact properties in hybrid materials was explained in terms of the impact fracture surface analysis by scanning electron microscope (SEM).