Based on Eley-Rideal kinetic mechanism, one dimensional mathematical model for selective catalytic reduction reaction was established, in order to simulate the SCR process in the catalyst channel. The thermal effect on the reaction and the side effect of ammonia oxidation in the channel were considered simultaneously in the modeling. The model was testified to be reliable by compared with the experimental data. By the model, the concentration and temperature distributions in the channel were simulated. The effects of catalyst structure parameters, such as the pitch, the shape of catalyst channel and the monolithic catalyst type, on de-NOX efficiency were studied emphatically. The simulation results would be as an important reference for the design of SCR catalyst in the practical application.