Sn-doped In2O3 (ITO) powder was prepared by co-precipitation through ion exchange method with the solution of InCl3 and SnCl4 center dot 5H(2)O under the condition of the different temperatures and different molar ratios of Sri to In. ITO precursor was analyzed by TG-DTA, and the morphology, phase composition and particle size of the powder were characterized by TEM and XRD. The effects of calcination temperature and molar ratio of Sn/In on the phase composition, particle size and conductivity were discussed. The results showed that the phase transformation occurs at a temperature of over 332 degrees C, and an ITO powder with perfect crystalline structure, minimum crystallite size, minimum powder resistance and the best conductivity can be prepared at the calcination temperature of 700 degrees C with 10% molar ratio of Sn/In. (c) 2008 Published by Elsevier B.V.