The oxidation resistance property of Y+ implanted H13 steel has been studied by ion backscattering. The Y concentration profiles were measured for Y+ implantation with various doses and current densities. The results show that the Y concentration profiles and peak concentrations are closely related with dose and current density. The oxidation resistance property is powerfully influenced by Y peak concentration. The oxidation model of H13 steel is modified due to the Y+ implantation. The oxygen diffusion is controlled. The oxidation barrier is formed after high temperature oxidation (800℃) for 10min and the oxidation speed is decreased by a factor of 8.