In this work, we have synthesized RuO2/graphene nanocomposites by using a facile one-step low-temperature hydrothermal process, where the graphene oxide is reduced to graphene and RuO2 is also formed and decorated on graphene sheets.Both X-ray diffraction (XRD) and scanning electron microscope (SEM) results show that the RuO2 has an amorphous structure and is dispersed well in the graphene sheets, which would be a promising electrode material for energy storage application.