Provided is a lithium secondary battery excellent in initial charge/discharge characteristics and high in capacity comprising lithium-rechargeable cathode and anode and a nonaqueous electrolyte, wherein at least one of the cathode and the anode contains one of the following (A), (B) and (C):
(A) a composite material comprising a carbon powder and a binder, which is treated with a silane coupling agent, (B) a composite material comprising a binder and a mixed carbon powder containing 70-99% by weight of a graphite powder and 30-1% by weight of a pseudo-graphitic carbon black, and (C) a composite material comprising a composite oxide powder of lithium and a transition metal, a conductive powder and a binder, which is treated with a silane coupling agent.