The wear behaviour of the Al-Mo-Ni coating on piston ring material against gray cast iron was investigated under dry and lubricated conditions at elevated temperatures. AISI 440C steel material, widely used in manufacturing piston ring for two-cycle engines, was coated by plasma spraying method including Al-Mo-Ni powders. Wear tests were carried out on a universal wear tester with a loading of 83, lK 200 and 300 N, and at elevated temperatures of 25, 100, 200 and 300 degreesC tinder dry and lubricated conditions. In conclusion, the material loss of the Al-Mo-Ni composite coating is increased with elevated temperatures under dry and lubricated sliding conditions. The material loss is sharply increased up to temperature point of 100degreesC under dry sliding condition while it is nearly constant after this point with test loading of 100N. Under lubricated conditions, the same tendency can be obtained for loading of 83 N. The wear mechanism is mixed mode such as abrasion, scuffing, delamination for dry conditions. Under lubricated conditions, for the lower temperature, the absorbed oil inclusions in the porosities postpone the wear in progress, resulting in easy friction. The wear mechanism of Al-Mo-Ni coating is predominantly abrasive, and delamination also occurs under heavy loading. The wear of the coating under lubricated conditions is nearly 10 times lower than that of dry conditions. (C) 2004 Elsevier B.V. All rights reserved.