Graphene, consisted of a single layer of carbon atom in a two-dimensional lattice, has superior electrical and physical properties that promise many exciting applications. In this study, graphenes were prepared from graphite powder by chemical method and their images were investigated by TEM and SEM. To develop high performance epoxy nanocomposites with good dispersion of graphenes and strong epoxy-graphene interfacial bonding, graphenes were amine-functionalized and the effects of the amine-functionalization on the curing behavior and physical properties of epoxy/graphene nanocomposites were studied. FTIR spectra confirmed the amine-functionalization. The physical properties of the nanocomposites were investigated by DSC, DMA, TMA, and impact tester. Fracture surfaces were investigated by SEM. The physical properties of the nanocomposites could be improved considerably by the amine-functionalization of graphenes. POLYM. ENG. SCI., 54:985-991, 2014. (c) 2012 Society of Plastics Engineers