Carbon was coated on the surface of Li2MnSiO4 to improve the electrochemical performance as cathode materials, which were synthesized by the solution method followed by heat treatment at 700℃ and the solid-state method followed by heat treatment at 950℃. It is shown that the cycling performance is greatly enhanced by carbon coating, compared with the pristine Li2MnSiO4 cathode obtained by the solution method. The initial discharge capacity of Li2MnSiO4/C nanocomposite is 280.9 mAh/g at 0.05 C with the carbon content of 33.3 wt%. The reasons for the improved electrochemical performance are smaller grain size and higher electronic conductivity due to the carbon coating. The Li2MnSiO4/C cathode material obtained by the solid-state method exhibits poor cycling performance, the initial discharge capacity is less than 25 mAh/g.