This paper presents a study on electrochemical performance and crystal structure of La3Ni2Sn7, a new anode material for rechargeable lithium ion battery. This compound showed a larger reversible capacity of 1000 mAh/cm(3) than that of graphite anodes. Good cycle performance was observed during electrochemical charge-discharge reaction. X-ray diffraction revealed that lithium ion inserted into host La3Ni2Sn7 without significant host-structural change and with small volumetric expansion of 0.4%. Accordingly, the good cycle performance is ascribable to the small volumetric change of the crystal lattice. (C) 2005 The Electrochemical Society.