We have investigated structural and surface property of transparent conductive Nb-doped titanium oxides (TNO) thin film with high conductivity of 10(-4) Omega cm order which were made by RF-magnetron sputtering at high deposition rates followed by an annealing in vacuum. The grain sizes of TNO evaluated by atomic force microscope were found to become larger by annealing at temperature higher than 500 degrees C. The measured work functions of the TNO films using ultra-violet light photoelectron spectroscopy were 5.02-5.47 eV, and depended on TNO grain size and on the amount of surface weakly bound oxygen that was estimated from peak area intensities of 0(1 s) X-ray photoelectron spectra. (C) 2010 Elsevier B.V. All rights reserved.