The effect of ultra-violet (UV) irradiation on the electronic structure and the surface resistance of an insulating SrTiO3(0 0 1) crystal is studied in this work. Upon UV irradiation, we show that the two-dimensional electron gas (2DEG) emerges at the insulating SrTiO3 surface and there is a pronounced change in the surface resistance. By combining the observations of the change in valance band and the resistance change under different environments of gas pressure and gas species, we find that UV-induced oxygen vacancies at the surface plays a major role in the resistance change. The dynamic of the resistance change at different oxygen pressures also suggests an alternative method of low-pressure sensing. (C) 2015 Elsevier B.V. All rights reserved.