Fe3O4/C composites have been prepared by sucrose calcining with Fe3O4 particles obtained from ferrous oxalate decomposition. The scanning electron microscopy (SEM) images show that Fe3O4 nanoparticles (Fe3O4 NPS) with average size of 200nm are embedded in the three-dimensional (3D) carbon-framework. As an anode material for rechargeable lithium-ion batteries, the Fe3O4/C composite delivers a reversible capacity of 773mAhg−1 at a current density of 924mAg−1 after 200 cycles, higher than that of the bare Fe3O4 NPS which only retain a capacity of 350mAhg−1. When the current density rises to 1848mAg−1, Fe3O4/C material still remains 670mAhg−1 even after 400 cycles. The enhanced high-rate performance can be attributed to the 3D carbon-framework, which improves the electric conductivity, relaxes the strain stress and prevents the aggregation of Fe3O4 particles during the charge/discharge process.