Iron (III) doped titanium dioxide film with high visible light photocatalytic activity was prepared using the modified sol-gel method, in which, none of organic solvent was used and all the films were prepared at low temperature. The as prepared films were characterized by wide angle X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (DRS), electron paramagnetic resonance (EPR) and atomic force microscope (AFM). Characteristic results clearly show that the architecture of Fe3+ doped TiO2 is composed of mixed-phase crystal textures of anatase and brookite, and crystal size keeps at approximately 10 nm. After Fe (III) was successfully doped into titania lattice and partly substituted Ti (IV), absorbance of films in visible light displays obvious red shift. The photocatalytic activities of Fe3+ doped TiO2 films show their best efficiency at an optimal atomic ratio of Fe to Ti of 1.2:100. The effect of dopant and preparing conditions on their structure and photocatalytic activities were investigated in detail.