Graphene, as the perfect 2D carbon atomic material available to us, has recently attracted a large amount of attention due to its excellent properties,such as high mechanical stiffness, high fracture strength, high thermal conductivity and super electron mobility.Among these properties, the high stiffness and strength make graphene owning an outstanding potential as a key reinforcement in composites.In the past years, many researchers have focused on fabricating composites of graphene oxide in a polymer or metal matrix.As a result of low mechanical behavior and difficulty in uniform dispersion, graphene oxide (GO) in the matrix can just produce the relatively poor strengthening effect.Fortunately, the reduced graphene oxide (RGO) can possess the mechanical properties close to those of single-layer graphene.