An easy approach for the preparation of graphene nanosheets is reported. The graphene is fast obtained within half an hour by ultrasonication under mild condition. The reduced graphene nanosheets are characterized by scanning electron microscope, atomic force microscope, X-ray diffraction and Raman spectroscopy. When used as anode material for a Li-ion battery, the graphene electrode exhibits a high initial charge capacity of 792 mAh g(-1) and maintains a stable capacity of 590 mAh g(-1) at the 20th cycle. The good cycling stability should be ascribed to the ultrasonication treatment which could prevent the aggregation of graphene sheets during the reduction process. (C) 2013 Elsevier B.V. All rights reserved.