A series of Ce x Pr 1−x O 2−δ mixed oxides were synthesized by a sol–gel method and characterized by Raman, XRD and TPR techniques. The oxidation activity for CO, CH 3 OH and CH 4 on these mixed oxides was investigated. When the value x was changed from 1.0 to 0.8, only a cubic phase CeO 2 was observed. The samples were greatly crystallized in the range of the value x from 0.99 to 0.80, which is due to the formation of solid solutions caused by the complete insertion of Pr into the CeO 2 crystal lattices. Raman bands at 465 and 1150cm −1 in Ce x Pr 1−x O 2−δ samples are attributed to the Raman active F 2g mode of CeO 2 . The broad band at around 570cm −1 in the region of 0.3≤x≤0.99 can be linked to oxygen vacancies. The new band at 195cm −1 may be ascribed to the asymmetric vibration caused by the formation of oxygen vacancies. The TPR profile of Pr 6 O 11 shows two reduction peaks and the reduction process is followed: PrO1.83⟶530 °CPrO1.61⟶650 °CPrO1.5. The reduction temperature of Ce x Pr 1−x O 2−δ mixed oxides is lower than those of Pr 6 O 11 or CeO 2 . TPR results indicate that Ce x Pr 1−x O 2−δ mixed oxides have higher redox properties because of the formation of Ce x Pr 1−x O 2−δ solid solutions. The presence of the oxygen vacancies favors CO and CH 3 OH oxidation, while the activity of CH 4 oxidation is mostly related to reduction temperatures and redox properties.