Strontium was introduced into CeO2-ZrO2 mixed oxides(CZ) by doping and impregnation methods,and then Pt was impregnated on the Sr-modified CZ to obtain the catalysts.X-ray diffraction(XRD),X-photon spectra(XPS),high-resolution transmission electronic microscopy(HRTEM) and H 2 temperature programmed reduction(TPR) were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity(OSC) was evaluated with CO serving as probe gas.The results showed that the incorporation of Sr 2t in the lattice of CZ could promote the OSC properties by increasing the structure defects and enhancing the diffusion rate of oxygen from bulk to surface.For the Sr-impregnated sample,the strong metal-support interaction(SMSI) between Pt and CZ was interrupted,since Sr covered partial surface Ce species.Such interruption retarded the back-spillover effect occurring at the Pt/Ce interface at low temperature,resulting in the loss of OSC.Meanwhile,it was found that a part of impregnated Sr 2t could partially diffuse from the surface to the inner atomic layers of CZ and partially incorporated in the lattice during the calcination.The OSC performance of Sr-impregnated sample therefore climbed remarkably with the rise of temperature. Strontium was introduced into CeO2-ZrO2 mixed oxides (CZ) by doping and impregnation methods, and then Pt was impregnated on the Sr-modified CZ to obtain the catalysts. X- ray diffraction (XRD), X-photon spectra high-resolution transmission electronic microscopy (HRTEM) and H 2 temperature programmed reduction (TPR) were carried out to characterize the micro-structure and reducibility of catalysts. The oxygen storage capacity (OSC) was evaluated with CO serving as probe gas. showed that the incorporation of Sr 2t in the lattice of CZ could promote the OSC properties by increasing the structure defects and enhance the diffusion rate of oxygen from bulk to surface. For the Sr-impregnated sample, the strong metal-support interaction (SMSI) between Pt and CZ was interrupted, since Sr covered partial surface Ce species .uch interruption retarded the back-spillover effect occurring at the Pt / Ce interface at low temperature, resulting in the loss of OSC.Meanwhile, it was found that a part o f impregnated Sr 2t could partially diffuse from the surface to the inner atomic layers of CZ and partially incorporated in the lattice during the calcination. The OSC performance of Sr-impregnated sample likely climbed remarkably with the rise of temperature.