Reduced graphene oxide nano-sheets encapsulated copper spherical particles (Cu@rGO) were obtained through a simple electrostatic self-assembly process followed by chemical reduction. The oxidation resistance of Cu spherical particles was considerably enhanced by the coating of rGO nano-sheets. XRD results show that the core-shell structured Cu@rGO did not exhibit any sign of oxidation in air after storage at room temperature for 70 days or after heat treatment at 130 C for 1.5 h. Furthermore, the rGO wrapped on the surface of Cu particles could transfer the two-dimensional rGO nano-sheets into three-dimensional (3D) networks. The Cu@rGO particles with 3D structure might have promising potential applications in thermal management, electrically conductive interconnection, electrodes, etc.