In this study, CeZr_0.5TiaO_x (with a = 0, 1, 2, 5, 10) catalysts were prepared by a stepwise precipitation approach for the selective catalytic reduction of NO_x with NH₃. When Ti was added, all of the Ce-Zr-Ti oxide catalysts showed much better catalytic performances than the CeZr_0.5O_x. Particularly, the CeZr_0.5Ti₂O_x catalyst showed excellent activity for broad temperature range under high space velocity condition. Through the control of pH value and precipitation time during preparation, the function of the CeZr_0.5Ti₂O_x catalyst could be controlled and the structure with highly dispersed CeO₂ (with redox functions) on the surface of ZrO₂-TiO₂ (with acidic functions) could be obtained. Characterizations revealed that the superior catalytic performance of the catalyst is associated with its outstanding redox properties and adsorption/activation functions for the reactants.