MoS2-reduced graphene oxide (RGO) composites were synthesized via a facile microwave assisted reduction of graphene oxide in MoS2 precursor solution and subsequent annealing in N2/H2 atmosphere at 800 °C for 2 h. Their morphology, structure and electrochemical performance were characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, N2 adsorption-desorption isotherm, cyclic voltammetry and electrochemical impedance spectroscopy. The MoS2-RGO composites with different RGO loadings were applied as anode materials of sodium ion batteries (SIBs) and they exhibit a maximum reversible specific capacity of about 305 mAh g-1 at a current density of 100 mA g-1 after 50 cycles and excellent rate performance. The results demonstrate that MoS2-RGO could be a potential electrode material for rechargeable SIBs.