The effects of the combination of silane functionalized hollow glass beads (silanized HGBs), acid functionalized carbon nanotubes (oxidized CNTs), and short carbon fibers (SCFs) on the tensile properties of epoxy (EP) resin were investigated. The combined utilization of silanized HGBs, oxidized CNTs and SCFs led to a pronounced synergy in the tensile properties of the SCF/HGB/CNT/EP composites. The composites exhibited greater tensile strength and Young's modulus than the neat EP, clearly. The mechanism of such synergetic effect was analyzed by tensile fracture studies using SEM. In addition, by analyzing the DSC curves, the curing temperatures of the composites were obtained.