Fe3O4 has been regarded as one of the sustainable alternatives for anode materials of Li-ion batteries (LIBs), but the severe volume expansion and agglomeration of Fe3O4 nanoparticles pose limitations to the lithium storage capability. In this paper, Fe3O4 nanoparticles are loaded on the carbon derived from inner pomelo pericarp to form Fe3O4/C composite. Benefiting from the synergistic effect of the good electronic conductivity of the biochar and the high capacity of Fe3O4 nanoparticles, the composite delivers a pronounced reversible capacity of 1003.3mAhg−1 after 200 cycles at 100mAg−1, and reveals an impressive high rate capacity of 634.6mAhg−1 at 500mAg−1 with the capacity fading of 0.074% per cycle, suggesting the great potential as anode materials for LIBs. The mineral substances of uniformly distributed KCl and CaCO3 in the biochar play an important role in enhancing the electrochemical performance of the composite.