CrN coatings were deposited on 316L stainless steel substrate at the bias voltage from 0 V to -100 V using Cr cathodes by a cathodic arc plasma deposition system.The influences of bias voltage on the CrN coating structure and its tribological behaviors in seawater were investigated by using the ballplanar reciprocating friction and wear tester.The results show that,along with increasing of the bias voltage,the structural morphology of CrN coating becomes denser,the hardness is increased at first and then keep stable,and the adhesion between 316L and coating is firstly increased and then decreased,with optimal force in -50 V to-75 V.The friction coefficient of the CrN coatings is low in seawater (about 02 to 03),and it is decreased with the increasing of the bias voltage.The wear rate of the CrN coatings is decreased and then increased with the increasing of the bias voltage,when in -50 V to -75 V,the wear rate is quite low.The coating deposited at the bias voltage of-50 V to-75 V has the optimal comprehensive mechanical properties.