SUS 440C martensitic stainless steels (16Cr-1C) coated with diamond-like carbon (DLC) by arc ion deposition were studied. The technology of surface modification can provide the better surface characteristics and wear resistance,especially higher hardness. SUS 440C martensitic stainless steels (16Cr-1C) coated with diamond-like carbon (DLC) by arc ion deposition were studied. The technology of surface modification can provide the better surface characteristics and wear resistance,especially higher hardness.