The aluminizing treatment on the surface of commercial pure copper with addition of rare earth compound CeCl3 was carried out. The followed internal oxidation of the aluminized copper was also carried out in the industrial nitrogen gas flow. The influences of the aluminizing and internal oxidization processing time on the thickness, hardness profile and microstructure were investigated. Results show that the addition of rare earth oxide CeCl3 has great accelerating effect on the aluminizing and internal oxidation processing. The hardness of the surface Al2O3 dispersion hardened copper composite layer by means of internal oxidation with addition of rare earth compound is higher than that of the without addition. The internal oxidation mechanism of the aluminized layer on copper matrix is comprehensive processes of the oxygen inner-toward diffusion and localized internal oxidation of the inner-toward diffusion of aluminum.