Abstract: In order to improve the catalytic property of the plate-type De-NO_x catalysts, TiO₂-montmorillonite and TiO₂-acid treated montmorillonite were used as the composite carriers for the preparation of the catalyst. XRF, XRD, N₂-adsorption, Raman, H₂-TPR and NH₃-TPD analysis were carried out to investigate the physical and chemical properties of the catalysts. The result shows that the BET surface area and the attrition strength of the catalysts with the using of composite carriers are higher than that of the traditional V₂O₅-MoO₃/TiO₂ catalyst. Alkali metal element (Na, K) contained in the montmorillonite has negative effect on the reducibility and acidity of V₂O₅-MoO₃/TiO₂-montmorillonite catalyst, which is unfavorable for the catalytic performance. The acid treatment improves the BET surface area of the montmorillonite, and decreases the alkali metal element content simultaneously. As a result, the catalytic activity of V₂O₅-MoO₃/TiO₂-acid treated montmorillonite catalyst is relatively high. Addtionally, this catalyst also exhibits well SO₂ and H₂O resistance.