A facile method is developed to in situ one-step synthesize CoFe2O4/graphene (CFO/GN) nanocomposites as a promising high-performance anode for lithium-ion batteries. This method involves two processes occurring simultaneously: Co2+ and Fe2+ ions co-precipitate homogeneously on the surface of graphene oxides by using urea as the precipitant, while in situ reduction process reduces graphene oxides at the same time. As a consequence, the nanocomposites of CFO/GN self-assembled into a three-dimensional (3D) network architecture, in which CoFe2O4 nanoparticles with the diameter of 50-80nm uniformly dispersed on graphene sheets. The as-synthesized CFO/GN nanocomposites exhibit a high specific reversible capacity up to 937.73 mAh g−1 with high charge/discharge reversibility at high current densities of 1000mAg−1. In addition, it shows superior rate capability and good capacity retention of 69.5% after 50 cycles. The improved cyclic stability can be attributed to the synergistic interaction between uniformly dispersed CoFe2O4 nanoparticles and graphene, which offers the fast diffusion of Li ions (diffusion coefficient: 1.29×10−13 cm2 s−1) and low internal resistance (equivalent series resistance: 138.49Ωcm−2).