Abstract: Rutile and anatase TiO2 and its poly(butyl acrylate) composites latexes were used to finish cotton fabric. The aging resistance, ultraviolet resistance and sterilization properties of finished cotton fabric under UV-irradiation were measured, in order to understand the response mechanism of different crystal TiO2 particles to UV-irradiation and its effect on the performances of finished cotton fabric. It was found that, rutile TiO2 finished cotton fabric exhibits excellent ultraviolet resistance, outstanding aging resistance and bad sterilization properties attributing to the strong optical absorption and diffuse scattering of rutile TiO2 particles, while anatase TiO2 finished cotton fabric excellent ultraviolet resistance, outstanding sterilization and accelerated aging properties attributing to the strong photocatalytic effect of anatase TiO2 particles. The strong photocatalytic effect under UV-irradiation can induce many strong oxidizing free radicals, which can effectively kill bacteria and simultaneously break the molecular chain of fiber inevitably. Thus, the crystal of TiO2 and its negative effects should be careful considered during function finishing of fabric.