Ce x Ti 1- x O 2 mixed oxides of different mole ratios ( x =0, 0.1, 0.2～0.9, 1.0) were prepared by co precipitation of TiCl 4 with Ce(NO 3) 3 and then loaded with different amounts of CuO. The effects of CuO on NO+CO reaction were investigated, and the structure and reductive properties of various CuO/Ce x Ti 1- x O 2 were characterized by the methodologies of BET, TPR and XRD. The results show that different Ce/Ti mole ratios and calcination temperatures induce changes of structure and reductive properties of the Ce x Ti 1- x O 2 mixed oxides. When x =0.1～0.5, amorphous CeTi 2O 6 phase mainly forms at 650 ℃ compared to the formation of CeTi 2O 6 which crystallizes at 800 ℃. When x >0.6, some TiO 2 enters the CeO 2 lattice and a CeO 2 TiO 2 solid solution is formed. The activity of 6%CuO/Ce x Ti 1- x O 2 calcined at 650 ℃ is largely affected by the x values, which is the highest when x =0.3, 0.4 and 0.9. The NO conversion reaches 70% at a reaction temperature of 150 ℃. By comparison, the x values have little effect on the activity of 6%CuO/Ce x Ti 1- x O 2 calcined at 800 ℃ . There are strong interactions between CuO and CeTi 2O 6, i.e., formation of the CeTi 2O 6 phase shifts the CuO reduction peak temperature from 380 to 200 ℃, and CuO, in turn, shifts the CeTi 2O 6 reduction peak temperature from 600 to 300 ℃. Ce x Ti 1- x O 2 mixed oxides of different mole ratios (x = 0, 0.1, 0.2-0.9, 1.0) were prepared by co precipitation of TiCl 4 with Ce (NO 3) 3 and then loaded with different amounts of CuO . The effects of CuO on NO + CO reaction were investigated, and the structure and reductive properties of various CuO / Ce x Ti 1-x O 2 were characterized by the methodologies of BET, TPR and XRD. The results show that different Ce / Ti mole ratios and calcination temperature induce changes of structure and reductive properties of the Ce x Ti 1-x O 2 mixed oxides. When x = 0.1-0.5, amorphous CeTi 2O 6 phase mainly forms at 650 ° C compared to the formation of CeTi 2O 6 which crystallizes at 800 ° C. When x> 0.6, some TiO 2 enters the CeO 2 lattice and a CeO 2 TiO 2 solid solution is formed. The activity of 6% CuO / Ce x Ti 1-x O 2 calcined at 650 ° C. is largely affected by the x values, which is the highest when x = 0.3, 0.4 and 0.9. The NO conversion reaches 70% at a reaction temperature of 150 ° C. By comparison, the x values ​​have little effect on the activity of 6% CuO / Ce x Ti 1- x O 2 calcined at 800 ° C. There are strong interactions between CuO and CeTi 2 O 6, ie, formation of the CeTi 2O 6 phase shifts the CuO reduction peak temperature from 380 to 200 ° C., and CuO, in turn, shifts the CeTi 2 O 6 reduction peak temperature from 600 to 300 ° C.