In this study, nanodiamond (ND)-electroless Ni plating composite coating was synthesized for high wear resistance and low friction. The ND-Ni plating composite coating was prepared from electroless Ni plating solution dispersing diamond nano particle (DNP) on S50C substrate. Heat treatment to increase hardness of electroless Ni plating was conducted in this coating. Tribological properties of the ND-Ni plating composite coating was investigated under three lubricant conditions (no lubrication, water lubrication and 1wt.% DNP dispersion). Under the DNP dispersion, the friction coefficient of ND-Ni plating composite film and Ni plating coating were lower than other conditions. Severe wears after the friction tests were observed on the ND-Ni plating composite coating under no lubrication, however only small protrusion of the composite film tested under the DNP dispersion was worn.