Effects of radiation on thermal and mechanical properties of modified epoxy resin and hydrogenated bisphenol-A type epoxy resin based shielding materials have been investigated. The onset temperature of KNS-201 has been increased with increase in the radiation dose, but that of KNS-301 has been decreased at radiation dose above 0.5 MGy. Also the thermal expansion coefficient of shielding material of KNSs-301 has been affected less than that of KNS-201 by radiation. At radiation dose up to 0.1 MGy, the tensile strength, compressive strength and flexural strength of the shielding material of KNS-301 has been increased with increase in the radiation dose. In contrast, that of KNS-201 has been decreased with increase in the radiation dose.