The hierarchical architecturing and hybridization of iron oxide is very important for achieving multifunctional capability that makes it possible for practical applications. In particular, hierarchical structure constructed by graphene nanosheets and iron nanoparticles takes advantages of 3D interconnected structure in terms of a large accessible area, fast mass and ion transport, and structural integrity. In this study, hierarchically structured reduced graphene oxide (hrGO)/α-Fe2O3 nanobox hybrids (hrGO/α-Fe NBhs) are synthesized via a hydrothermal self-assembly process. The 3D porous structure of hrGO/α-Fe NBhs is constructed, while α-Fe2O3 nanoboxs (NBs) in a proximate contact with the hrGO surface are simultaneously nucleated and grown during a hydrothermal treatment. The discrete α- Fe2O3 NBs are uniformly distributed on the surface of the hrGO/α-Fe and confined in the 3D architecture, thereby inhibiting the restacking of rGO layers and maximizing their functionalities.