The surface of graphene (GE) was modified with a silane coupling agent, and its surface characteristics were investigated. Epoxy resin/GE nanocomposites were prepared via solution blending. The effect of the GE content on the thermal stability, flexural properties, impact strength, and morphology of the nanocomposites was studied. The thermal stability of the epoxy resin increased with the addition of pristine GE and surface‐modified GE. The flexural strength, elastic modulus, and impact strength of the nanocomposites with surface‐modified GE increased significantly with increasing GE content. Scanning electron microscopy images of the nanocomposites with surface‐modified GE show a ductile deformation morphology, which is consistent with their high impact strength.