Tensile and thermal properties of diglycidyl ether of bisphenol A(DGEBA)/4,4-methylene dianiline(MDA) modified with MDA-endcapped carboxyl-terminated butadiene acrylonitrile rubber(CTBN) were studied by universal testing machine(UTM) and thermal analyzer(TA). When MDA-endcapped CTBN content increased, elongation increased and tensile strength, Young's modulus and glass transition temperature decreased. The tensile energy was slightly increased until 10 phr of MDA-endcapped CTBN, and after that phr the tensile energy decreased.