Abstract: Hollow glass microsphere(HGM)/epoxy syntactic foams were prepared with epoxy filled with HGM, The density of the syntactic foams was maintained 0.56-0.91 g/cm³. Viscosity, mechanical properties, dynamic mechanical properties and thermal insulation properties of the syntactic foams were investigated with respect to HGM content. The results show that surface coupling modification improves surface lipophilicity of HGM, thus increases the compatibility and interfacial property between HGM and resin matrix, which is beneficial to enhancing the property of syntactic foams. The viscosity of system increases with HGM content increasing and decreases with temperature increasing. The compressive, flexural and tensile strength decrease with increasing HGM content to some extent, the specific strength changes little, making a high degree of weight saving. With the incorporation of HGM, the glass transition temperature of HGM/epoxy syntactic foams shifts to low temperature and the storage modulus first decreases then increases, thermal conductivity decreases from 0.203 W/(m·K) of neat epoxy to 0.126 W/(m·K) of syntactic foams containing 40wt% of HGM, there is a significant improvement on damping and thermal insulation properties of HGM/epoxy syntactic foams.