Abstract: Based on commercial as-cast Mg-Si alloy, nanoporous silicon/carbon composite anode was prepared by chemical etching combined with carbon coating technology.The crystalline phases, chemical composition and microstructure of the anode were characterized by SEM, XRD and EDS, and its electrochemical properties were studied. The results show that the anode has a typical 3D bicontinuous nanoporous structure, and carbon layer uniformly coats on the surface of nanoporous silicon. Moreover, the anode delivers the first charge/discharge capacity of 724.44/1404.49 mA·h/g at a current density of 0.1 C with the cycle life of over 800 times.It can be used normally in a wide temperature range of-30 ℃-50 ℃.