Size, shape and processing of the inorganic fillers are important for improving properties of nanocomposites. In this paper, a novel nanofiller containing mesoporous silica(MS) and fibrous sepiolite(SE) was prepared by in situ deposition method. EP/MS-SE nanocomposite was obtained by adding MS-SE to epoxy resin(EP) matrix. Morphologies and mechanical properties of the new ternary nanocomposite were investigated. For purpose of comparison, the corresponding binary nanocomposites, i.e., EP modified with either MS or SE, were tested as well. The test results of mechanical properties show that MS improves the strength of EP and SE obviously enhances the toughness of EP, but oM-MS exhibits synergistic effect on toughening and reinforcing of EP at the same time. Dynamic mechanical analysis revealed that the glass transition temperature and storage modulus of the EP/MS-SE nanocomposite was higher than those of pure EP.