Abstract: CrN coatings with different composition were deposited using a close field unbalanced magnetron sputter ion plating system. Wear of CrN hard coatings was investigated by pin-on-disc tester and micro-abrasion tester. Generally the micro-abrasive wear rate of the CrN coatings was governed by OEM rather than by the bias. Specific wear rate from pin-on-disc test of coatings deposited under different N2 flow which was controlled by opitical emossion monitor was not reflected by the changes of wear resisitance due to different structure and properties. Hole drilling test indicated that the number of holes increased significantly when the micro-abrasive wear rate was less than a critical value, while the specific wear rate changed little.