Abstract: Ce-TiO₂ and Ce-Co-TiO₂ powders were prepared by the sol-gel hydrothermal method with butyl titanate as the source of Ti, cerium nitrate as the source of Ce, cobalt nitrate for Co source. The modified TiO₂ catalysts were characterized with BET, XRD, SEM, UV-vis, XPS and NH₃-TPD. The NO reduction efficiency by visible light over the modified TiO₂ catalysts was carried out. The experimental results show that the catalyst Ce (1% molar)-Co (5% molar)-TiO₂ prepared under the conditions of 24 h hydrothermal synthesis at 160 and 200 ℃of calcination showed the best performance. At room temperature, the visible light catalytic efficiency of the catalyst reached 92.69% when the NO initial concentration was 762 μg/m³. When the NO initial concentration was 1148 μg/m³, the visible light catalytic efficiency could still reach 85.94%, which was improved by nearly 50% compared with pure TiO₂. Moreover, it was found that in the resistance of SO₂ and continuous usage, the efficiency of the Ce (1%)-Co (5%)-TiO₂ catalyst was better than the commercial catalysts (TiO₂ with V₂O₅ doping).