The effect of ART reagent on the frication performance of 45 steel/cast iron pair is studied by using an improved friction apparatus. The ART reagent is added to the pair, and then the friction experiment is carried out at constant load and velocity under air condition. Emphases are mainly put on the mechanisms of surface modification and abrasion - resistant rule. Investigation by microscope indicates that many particles, such as the elements of ART reagent, are embedded into the surface. The micro-penetration hardness and surface roughness are greatly increased and decreased respectively, which demonstrates the pronounced abrasion-resistant effects of ART reagent.