Fe3O4/reduced graphene oxide (Fe3O4/RGO) nanocomposite was prepared by a facile interface reaction and subsequent in situ reduction process. The electrochemical performances of the as-prepared Fe3O4/RGO nanocomposite were evaluated in coin-type cells. It delivers high reversible capacity of 1025 mAh g(-1) at 100 mA g(-1) after 50 cycles and outstanding cycle stability. Even after 800 cycles at various rates from 100 to 4000 mA g(-1), the capacity still retains 959.4 mAh g(-1) at 100 mA g(-1). A transmission electron microscopy image has shown the flexible interleaved structure of nanocomposite, and the interface reaction is also benefit to ensure strong interfacial interaction between Fe3O4 nanoparticles (50 nm) and RGO nanosheets. The designed structure plays key role in improving electrochemical performance. The Fe3O4/RGO nanocomposite with super long cycling life will be an ideal candidate of anode material for lithium ion batteries. (C) 2012 Elsevier B. V. All rights reserved.