The abnormal wears such as unfair-wear and early-wear happen in the earn shaft surface of automobiles. These abnormal wears make efficiency of engines decrease and threaten safety of automobiles. The wear characteristics of the cam shaft is very important for the automobile safety. The cam shaft is surface-hardened by the high frequency induction. In this study, we investigated the wear characteristics of the hardened surface with a SM53C steel. The wear characteristics is examined according to the hardened depth and the amount of load.