Anatase and rutile TiO₂ surfaces have been investigated with a computationally efficient semiempirical tight binding method: self-consistent-charge density functional tight binding (SCC-DFTB). SCC-DFTB predicts a band gap of  anatase TiO₂ surface of 2.3 eV comparing with one of rutile TiO₂ surface of  1.9 eV. The OH group has been found when hydrogen adsorded  on the anatase (001) surface and water molecules on rutile (110)  surface.