MgFe2O4/reduced graphene oxide composites (MFO/RGO) were prepared via a facile microwave assisted reduction of graphene oxide in MFO precursor solution, and used as anode materials for sodium ion batteries (SIBs). Their morphology, structure and electrochemical performance were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption-desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The results show that MFO/RGO composite with 20 wt.% RGO exhibits a maximum reversible capacity of about 347.5 mAh g-1 at 50 mA g-1 after 70 cycles with good cycling stability. The excellent electrochemical performance of MFO/RGO composites should be attributed to the synergistic effect of MFO and RGO to form a porous conductive network structure which offers the increased specific surface area, the facilitated electron transfer ability and the effective buffering of volume expansion.