Abstract： Nano-TiO₂ thin film was prepared by TiO₂ colloid on quartz glass surface by deposition method. The effect of TiO₂ colloid concentration， sedimentation time， and number of layers on the effective film thickness and sedimentation behavior was investigated. Deposition adsorption types of TiO₂ nano-particles were discussed. The results show that the maximum effective film thickness increases with the increase of TiO₂ colloid concentration. The optimum coating times have no concern with TiO₂ colloid concentration， which decrease with prolongate of sedimentation time. The sedimentation of TiO₂ nano-particles on quartz glass analyzed by the gas adsorption theory of B.E.T. and Langmuir isothermal adsorption conforms to experimental results.

Keywords： TiO₂ nano-particle；sedimentation； thin film； effective film thickness； sedimentation model