Using chemical vapor deposition method, a nano-Si@C composite with a core-shell structure was obtained by robust thin carbon layer coated in situ on nano-Si surface, which solved the problems of huge volume change and poor conductivity from Si. Experimental results show that nano-Si@C composite exhibits excellent electrochemical properties, such as high initial coulombic efficiency of 87.0%, high capacity of 1 133 mA·h·g^-1 after 100 cycles, and high capacity retention rate. Furthermore, the transmission electron microscopy images present strong structural stability of the composite with robust core-shell structure during the discharging/charging cycles, benefiting to improve the cycling stability of the electrode.