PURPOSE: To provide a combination of slide members, one of which is a steel, and which provides excellent slide characteristics.

CONSTITUTION: A cylinder liner 1 consists of 0.25-2.2% in wt.% CO and a steel containing 0.6-9.0% one or two more kinds of Cr, Mo, W, and V and hardness of an inner peripheral slid surface is HV 330-650. An inner peripheral surface may be covered with a thin soft film 8 worn in a short time for a purpose of initial drape properties. The outer peripheral surface of a piston ring 5 is covered with a rigid film 6, such as a CrN film or a Tin film, through a PDV method.