TiO2 films were prepared by dc reactive magnetron sputtering. The UV-Vis spectra and PL spectra of samples before and after heat treatment were studied in detail. An absorption peak (496 nm) in UV-Vis spectra and an emission shoulder (496.5 nm) in PL spectra are observed clearly. The analysis of X-ray photoelectron spectroscopy (XPS) indicates that the lattice oxygen can be removed by heat treatment to form the Ti3+ and oxygen vacancies. Taking the XPS analysis and theory calculation into consideration together, it can be concluded that the absorption peak (496 nm) in UV-Vis spectra and the emission shoulder (496.5 nm) in PL spectra are attributed to the d-electron transition of Ti3+ in TiO2 films.