We carried out the experiments on the wear of the materials for rolled steel type by Amsler universal wear testing machine. In these experiments, by rolling friction with slightly sliding friction we have experienced the resistance of a carbon steel containing about 0・55% of carbon with various structues to wear. The results are as follows : - (1) Rolled steel without any heat treatments has more resistance to wear than that of sorbitic structure (quenched at 820℃ and tempered at 600℃.). (2) The resistance to wear does not depend solely upon hardness, but also upon the structure of the steel. (3) The resistance to wear is greatly varied by the interchanging the position of the test piece. (4) Wear is chiefly affected by the steel powder which fallen off by abrasion, so that wear scarcely occured when the fallen powder were rubbed off during abrasion test. (5) Therefore, we come to conclusion that the were has little effect on the fatigue of materials.