Herein, we introduce a facile strategy for constructing graphene-decorated CoFe2O4 nanoparticles (CoFe2O4/rGO) as anode material for Li-ion batteries. The CoFe2O4/rGO composites are synthesized via single step chemical synthesis method, which involves an in situ oxidation-reduction process between GO and Fe2+ and the subsequent nucleation and growth of CoFe2O4 onto the surface of rGO. Well-designed experiments are conducted to investigate the detailed formation mechanism of this kind of CoFe2O4/rGO hybrid. The key feature of this work is that by using the oxidizing characteristic of GO and reducing characteristic of Fe2+, toxic reducing agents, such as hydrazine and hydroquinone, can be avoid skillfully, which make the procedure more straightforward and economical. Compared with the pure CoFe2O4, the as-prepared CoFe2O4/rGO with a low rGO content of 16.7 wt% shows enhanced Li ion storage behaviors. It exhibits a high initial reversible capacity of 901.2 mAh g−1 and a capacity retention of 80.7% after 100 cycles when operated at the current density of 200 mA g−1. Display omitted •A straightforward approach for constructing graphene-decorated CoFe2O4 was introduced.•FeOOH intermediate may be formed during the in situ reaction process.•CoFe2O4/rGO shows enhanced electrochemical properties as anode material.•The strategy can be extended to fabricate other MFe2O4 (M = Cu, Zn, Ni etc)/rGO.•Detailed formation mechanism of this kind of CoFe2O4/rGO hybrid was investigated.