A reduced graphene oxide (RGO)–magnetic oxide iron (Fe3O4) hybrid is prepared by homogenous coprecipitation and subsequent annealing. Characterization shows that Fe3O4 particles are nanoporous structures that anchor uniformly on the surface of RGO platelets. As an anode material for a Li ion battery, it has specific capacities for the first discharge and charge of 1528 and 1027mAhg−1 respectively, which is more than the theoretical specific capacity of Fe3O4. It shows good capacity retention of 818mAhg−1 after the 50th discharge. The total specific capacity of RGO–Fe3O4 is higher than the sum of those of pure RGO and Fe3O4 in the hybrid, indicating a synergistic effect of RGO and Fe3O4 for improving electrochemical performance. The RGO–Fe3O4 can be used as a high-performance anode material for Li-ion batteries.