Nickel-manganese-titanium oxides were studied for selective catalytic reduction of NO by XRD,H_2-TPR,NH_3-TPD and N_2 adsorption-desorption. The study found that the catalyst Ni_(0.4)Mn_(0.6)Ti_(10)-500 ℃ showed the best SCR activity,the reasons may be as follows: Ni_(0.4)Mn_(0.6)Ti_(10)-500 ℃ catalyst showed a larger specific surface area,the smaller average pore diameter,appropriate redox ability and the surface of a large number of acidic,that these are conducive to NH_3 under the condition of low temper...