Electrically conductive DLC(diamond-like carbon) coating technique has been developed by plasma based ion implantation with bipolar pulses. Energetic electrons and ions, which were induced by positive and negative pulses, respectively, were bombarded/deposited alternately on a substrate in hydrocarbon plasma. As a result, the resistivity of the DLC film decreased with the negative pulse voltage, and reached to 1 mΩcm at -20kV. Hardness of the film was 5.4GPa. TEM observation showed that the electrically conductive DLC films are composed of cluster of graphite-like aggregates. The technique can be applied for a metal separator in fuel batteries, where high conductivity and high electrochemical stability are needed.