The oxygen sensing properties of SrTiO3-based thin films have been investigated at room temperature. First, nondoped SrTiO3 was investigated. Although such a material is highly sensitive, its electrical resistance was too high and not feasible for practical use. Donor (Nb5+) could lower the resistance of SrTiO3; however, the sensitivity was lost. UV-light irradiation or t2-type acceptor (Cr3+) doping could lower the resistance and yet maintain the sensitivity. In contrast to t2-type acceptor doping, e-type acceptor (Fe3+) doping could lower the resistance; however, the sensitivity was lost. In this paper, we discuss the phenomena from the viewpoint of polaron-controlled carrier conduction.