The dispersion behaviors of copper oxide on the mechanical mixture of CeO2 and gamma -Al2O3 supports, CuO/CeO2 +,gamma -Al2O3, have been characterized by using XRD, LRS, XPS, UV-DRS, and TPR. The results show that copper oxide dispersed mainly on the surface of CeO2 support, provided that the loading amount of copper oxide does not exceed the dispersion capacity of CuO/CeO2, similar to1.2 mmol of CuO/100 m(2) of CeO2 (Dong, L.; Jin, Y. S.; Chen, Y. Sci. China (B). 1997, 40, 24). Increasing the CuO loading evidently leads to the formation of the dispersed copper oxide species on the surface of the gamma -Al2O3 support. The results have been tentatively discussed by using the incorporation model, which was proposed to describe the interaction between the dispersed species and the support previously (Chen, Y.; Zhang, L. F. Catal. Lett. 1992, 12, 51).