Nano-materials with high surface area have a reinforcing effect on the weak polymer materials. Addition of carbon nanotubes in polymer materials showed increase in mechanical and electrical properties because of high aspect ratio. Incorporating inorganic silica nanoparticles with carbon nanotube showed synergistic effect on multifunctional properties. In this study, the reinforcing effect of the silica-MWCNT hybrids in epoxy materials was investigated. The silica-MWCNT hybrids were prepared through by 2-step functionalization of MWCNT. Afterward, silica nanoparticles were covalently bonded onto functionalized MWCNTs. The morphologies of hybrids were observed through TEM analysis and were characterized by XPS and TGA. The MWCNT-silica hybrids was dispersed in epoxy materials and cured in autoclave. For investigating the reinforcing effect, tensile tests of hybrids/epoxy nanocomposites were conducted by ASTM D638. Addition of hybrids in epoxy materials caused increase in the tensile properties.