In aerospace applications research efforts are focusing on the design of advanced composite materials reinforced with nano fillers. Such advanced materials combine weight saving with multifunctional properties, including mechanical. In the present investigation, multiwall carbon nanotubes (MWCNTs) nanoparticles were dispersed individually by different size percentages into epoxy-based polymeric  nano composites. MWCNTs of 20 and 30 nm inner and outer diameters were reinforced with contents of 0.3, 0.6,and 0.9   % into epoxy matrix. Mechanical properties of Epoxy/MWCNTs  such as tensile strength, strain at break, impact energy,  and Vickers micro hardness .The design was done using design of experiments (DOE) using mixed full .The mechanical results revealed declining in tensile strength, strain at break and impact energy. While the  micro hardness values enhanced with addition of nano fillers into the epoxy matrix. Frequency response and shock absorption ratios have been severely affected by increasing ratios of nanometer materials. Where the results of mechanical tests showed a decrease in the rate of shock absorption. It is noticeable that the damping factor follows the same trend as the mechanical properties of epoxy nanoparticles.