As a promising anode material for Li-ion batteries, pristine Cr2O3 powder shows poor cycling performance due to its low electrical conductivity, the unstable of SET film and large volume change during cycling. To better understand these problems, anode material Cr2O3/C composite is prepared by high-temperature solid-state reaction, the lithiation mechanisms of the commercial Cr2O3 and Cr2O3/C composite electrodes have been investigated by electrochemical impedance spectroscopy (EIS), respectively. It is found that at the thermodynamic equilibrium voltage for the conversion reaction, the Nyquist plots of the commercial Cr2O3 and Cr2O3/C electrodes both consist of three semicircles and an inclined line, and the three semicircles are ascribed to the Li ion migration through the surface film, the electronic properties of the material, and a charge transfer step, respectively. Furthermore, an equivalent circuit including elements related to the electronic and ionic transport as well as the charge transfer process is put forward to simulate the experimental EIS data. Variations of kinetic parameters for lithiation of Cr2O3 as a function of potential in the initial discharge process are discussed in detail, and the reasonable explanation is given. (C) The Author(s) 2015. Published by ECS. All rights reserved.