Electrical resistivity, resistance to moist heat, transmittance and surface uniformity of In2O3 -ZnO (IZO) films prepared on soda lime glass (SG) substrate by rf-magnetron sputtering are investigated. These films show a poorer resistance to moist heat, a very rough uniformity and a high electrical resistivity as compared with those deposited on the coming glass substrates. These poor properties are originated by the diffusion of alkali metal from the soda lime glass and its rough surface. However, these properties can be improved by introducing a barrier layer Of SiO2 or TiO2 between IZO film and the soda lime glass substrate. There is no actual decrease of the average transmittance by introducing the barrier layers. Especially, IZO films deposited on the TiO2 barrier layer have higher resistance to moist heat and better surface uniformity than those deposited on the SiO2 barrier layer. (C) 2004 Elsevier B.V All rights reserved.