Zn/Ce redox flow battery (ZRFB) is emerging as a promising technology to store large amount of energy economically and efficiently, wherein a highly efficient positive electrode with a continuous and fast electronic and ionic transportation path is urgently desired. The unique nanostructure of reduced graphene oxide (RGO) paper electrode is prepared by a simply chemical reduction method, which facilitates transference of the electron and Ce3+/Ce4+ at the electrolyte/electrode interface. Thus ZRFB exhibits superior extent of charge (81.0%) and energy efficiency (71.3%). The results show RGO paper is a good candidate for positive electrode of ZRFB.