In sliding parts used by construction machines which is operate in harsh environment, one of the problems is that abnormal wear and seizure occur due to sliding under dusty condition. That severe wear is caused by sand dust intervening on the sliding surface. In order to prevent severe wear and seizure, a combination of an iron-based material and a soft metallic material such as brass is used on the sliding surface. And more,, we applied DLC (diamond-like carbon) coating on the surface of soft metallic materials. Specifically, we deposited segment structured DLC film on copper alloy, and evaluated its tribological characteristics by reciprocating sliding test. As a result, segment structured DLC coatings on soft metallic material showed more than three fold high wear resistance and seizure resistance as compared with DLC coated SUS440C, when dust is mixed in lubricant.