Epoxy resins, one of the most important thermosetting polymers, are currently used in advanced composites, coatings, microelectronics, and structural adhesives, because of their good chemical resistance, high stiffness, high strength, dimensional stability and excellent electrical insulation properties. But, a major limitation of neat epoxy resins, particularly those for high-temperature application is their inherent brittleness arising from the cross linked structure. In this study, polyketone/epoxy blend system was investigated in thermal stabilities and mechanical properties. These blends were cured with aromatic amine type curing agent i.e. 4,4’-Diaminodiphenyl Methane (DDM). The content of polyketone was varied in 0, 1, 2, 3, 4, and 5 wt%. The effects of poly ketone content on the thermal behaviors, such as cure behavior, glass transition temperature (Tg), and thermal stability, were studied by differential scanning calorimetry (DSC) and thermos gravimetric anaylsis (TGA). For the mechanical interfacial properties of the specimens, the critical stress intensity factor (KIC) test was performed and their fractured surfaces were examined by using a scanning electron microscope (SEM). Keywords: Glass transition, Curing of polymers, Nanocomposites, Thermal properties, Crosslinking