||CeO2 has been used for soot oxidation due to its high oxygen storage-released capacity. The activity of CeO2 could be greatly improved not only by precious metals, but also by rare earth metals and transition metals. CuO-CeO2 catalyst has been reported to show enhanced activity for several oxidation reactions. However, CuO-CeO2 catalyst in soot oxidation needs to be studied further. Thus, we introduced CuO-CeO2 based catalysts and investigated the way to imrpve their activity for soot oxidation. Ag is effective for O2 dissociation and CeO2 bulk oxygen utilization, improving the active oxygen generation of the Ag/CeO2. We prepared and examined a series of Ag/CuO-CeO2 catalysts with different Cu amounts. Through catalytic activity tests and characterizations of the catalysts for soot oxidation, the effect of Ag and Cu was verified. Ag supported on CuO-CeO2 showed the enhanced activity soot oxidation, and the relation with the properties of the catalyst will be discussed.