A method of the aluminizing treatment on the surface of Cu-Al-Y alloy with addition of rare earth compound CeCl3 in 1173K was carried out. The followed internal oxidation of the aluminized Cu-Al-Y alloy was also carried out in the commercial nitrogen gas medium to generate Al2O3 dispersed hardening copper matrix composites. The hardness distribution in aluminized layer and microstructure were studied. Results show that the addition of rare earth oxide CeCl3 has great accelerating effect on the aluminizing, the aluminized layer deeper and uniform than that not add CeCl3 at the same condition. It is possible to generate Al2O3 particles dispersed hardening layer depth reached about 200μm in the surface of specimens with aluminizing and internal oxidation technique.