TiAlN/TiN duplex coating is made on the surface of 40Cr steel by means of multi-arc ion plating technology. Carrying capacity and tribological properties of TiAlN/TiN duplex coating are investigated with a UMT-2 wear tester without lubrication. The surface morphology of wear specimens are observed by scanning electron microscope(SEM). Elements of wear scar center and their content are analyzed by EDS. Tribological properties of TiAlN/TiN coating are evaluated through comparing with 40Cr in friction coefficient and wear volume. The results show that tribological properties of TiAlN/TiN duplex coating is better than 40Cr. The TiAlN/TiN films is superior in reducing friction and wear resistance, and can successfully resist abrasive wear and adhesive wear.