The running-in behaviour of the metal carbon coating (WC/C) was evaluated with regard to its applicability as wear-resistant coating for key components in engines. Reciprocating wear tests under lubricated condition employing an oscillating friction wear tester were performed to investigate the tribological behaviors of the coatings in ambient environment. Confocal microscopy and scanning electron microscopy were used to observe worn surfaces and the wear scars on the steel balls. Elemental composition of the coating and worn surfaces were characterized using Auger electron spectroscopy. The friction behavior of WC/C coating was comparable to common carbon-based coatings. Thin tribofilm was formed on the worn surface of the steel ball due to material transfer and tribochemical reaction whereas there was no evidence of tribofilm generation on the coating surface. indicating the chemical innertness of WC/C coating.