The near surface of the H13 steel was implanted by using Plasma immersion ion implantation (PIII) system at constant bias voltage of −20 kV with varying nitrogen (N+ ) ion dose (3, 6, 9, 12, 15×1017 ions/cm2 ). The surface properties of the N+ ion implanted steel were investigated by measuring the microhardness, wear loss and friction coefficient. As increasing N+ ion dose (12×1017 ions/cm2), both wear property and surface hardness were increased. However, these properties were decreased as the incident ion dose increased over 12×1017 ions/cm2. The elemental depth profile and surface roughness were obtained with X-ray photoelectron spectroscopy (XPS) and surface roughness tester, respectively.