Fe-doped TiO2 thin films were prepared in situ on stainless steel substrates by liquid phase deposition, followed by calcination at various temperatures. It was found that some Fe3+ ions were in situ doped into the TiO2 thin films. At 400 °C, the film became photoactive due to the formation of anatase phase. At 500 °C, the film showed the highest photocatalytic activity due to an optimal Fe3+ ion concentration in the film. At 900 °C, the photocatalytic activity of the films decreased significantly due to the further increase of Fe3+ ion concentration, the formation of rutile phase and the sintering and growth of TiO2 crystallites. ; Department of Civil and Environmental Engineering