In this research work, an epoxy polymer- Carbon Black composite has been prepared and characterized regarding the effects of adding carbon black to epoxy polymer on some structural properties such as polymerization behavior, cross-linking reaction time and yield and some properties e. g. glass transition temperature (Tg), Young modulus (E) and flexural strength (σ). The cross-linking reaction and glass transition temperature were studied by Differential Scanning Calorimetry (DSC), and the mechanical tests were done by Universal Testing Machine.