Titanium dioxide/kaolinite nanocomposite was prepared by the sol-gel method, with layered kaolinite as a substrate and Ti( OC4 H9 )4 as a precursor. The effects of hydrolysis, drying and calcination on the production of nanometric titanium dioxide were discussed. The optimal conditions for preparation wereobtained through experiments. The 1- 10 nm thick monolayer anatase nano TiO2 crystal was produced under the conditions as follows: hydrolyzed at 37-42 ℃ for 4 h, dried at 70-80 ℃ for 1 h, and calcined at 550-650 ℃ for 3 h. The rate of degradation of 40 mg/ L azo dye and 20 mg/ L acid red dye can reach 96% and 81.45% , respectively.