The CeO2@TiO2 core-shell nanostructure catalyst prepared by a two-step hydrothermal method was used for selective catalytic reduction (SCR) of NOx with NH3 in this study.The catalyst presented the obvious core-shell structure,and the shell was amorphous TiO2 which could protect the active center from the SO2 erosion.The catalyst showed high activity and stability,excellent N2 selectivity and superior SO2 resistance and H2O tolerance.Characterizations such as TEM,HR-TEM,XRD,BET,XPS,NH3-TPD,and H2-TPR were carried out.The results indicated that the catalyst had large surface area and the active sites were well dispersed on the surface.The NH3-TPD,H2-TPR and XPS results implied that its increased SCR activity might be due to the enhancement of NH3 chemisorption and the increase of active oxygen species,both of which were conductive to NH3 activation.The excellent catalytic performance suggests that it is a promising candidate for SCR catalyst.