NOVELTY - A carbon-silicon composite material contains metal elements, and carbon nanofiber grown on surface of carbon base material containing amorphous silicon oxide particles. The metal element is iron, cobalt, nickel, copper, manganese, titanium, tin, silicon, zirconium, zinc, germanium, lead and/or indium, preferably iron, cobalt, nickel, copper and/or magnesium.    USE - Carbon-silicon composite material is used for cathode for lithium ion battery used in electric motor cars, hybrid electric vehicles, communication devices and small-scale electronic equipment.    ADVANTAGE - The battery comprising high electroconductive cathode made of carbon-silicon composite material has excellent initial charging and discharging characteristics. Since expansion and contraction of oxide particles is buffered, conductivity of cathode is improved.    DETAILED DESCRIPTION - A carbon-silicon composite material contains metal elements and carbon nanofiber grown on surface of carbon base material. The metal element is iron, cobalt, nickel, copper, manganese, titanium, tin, silicon, zirconium, zinc, germanium, lead and/or indium, preferably iron, cobalt, nickel, copper and/or magnesium. The carbon base material contains amorphous silicon oxide particles of formula: SiOx (x is more than 0.05 to less than 1.95). An INDEPENDENT CLAIM is included for preparation of carbon-silicon composite material. Ethanoate of iron, cobalt, nickel, copper, magnesium, manganese, titanium, tin, silicon, zirconium, zinc, germanium, lead and/or indium are dissolved in solvents such as distilled water, ethanol, isopropanol, glycol and/or glycerin to obtain catalyst solution. The silicon base material is added into the catalyst solution, stirred, stewed and dried to obtain catalyst-loaded silicon base material, and subjected to chemical vapor deposition method. The resultant product is blown into non-oxygen atmosphere, heated to 500-1200 degrees C to convert to carbon source gas containing carbon monoxide, methane, acetylene and/or ethane, chemically vapor deposited, and cooled to obtain carbon-silicon composite material.