Abstract: Two different surface treatments of diamond-like carbon(DLC) film preparation and sulfonitriding surface treatment were carried out on high speed steels.The wear resistance of high speed steels with different surface treatments running against cast iron alloy was investigated by using MM-200 friction and wear tester.The micrographs of the wear track were observed by SEM and the wear mechanism was analyzed.It is revealed that high speed steels with DLC films had better wear resistance compared to that of sulfonitriding surface treatment with the speed of 200 r·min-1 and the load of 50 N,no matter under conditions of oil lubrication or dry friction.