The crystal structure and electronic band structure of undoped and Fe-doped anatase TiO2 have been investigated by using the plane-wave ultrasoft pseudopotential method in the generalized gradient approximation (GGA). The calculation shows that Fe-doping introduces a localized level and narrowing of band gap in TiO2. The t2g state of the dopant plays a significant role in red-shift of spectrum. The previous prediction is confirmed by our experiment.