The carbon steel is used for all industrial materials, but theory on the heat treatment of carbon steel contains various difficult factor. In this paper, therefore, study on the wear loss of some quenched carbon steels and some spherodized carbon steels. Results obtained are as follows 1. It is plain enough that between wear loss and residual stress exist stress-abrasion limit. 2. Wear loss of spherodized carbon steel is less than normal structure carbon steel. 3. Spherodized pearlite remarkably appear at 680℃ from 3 to 5 hour.