The CdSnO3 semiconducting oxide that can be used as a gas-sensitive material for detecting ethanol gas is reported in this paper. CdSnO3 powders were prepared by a chemical co-precipitation synthesis method. The preparation conditions were carefully controlled. After calcinations at 500 degreesC for 6 h, the n-type semiconductor gas-sensing material was obtained. The phase and microstructure of the obtained powders were characterized by X-ray diffraction (XRD). The product corresponded to a small particle size range of 1-3 mum and high surface area of 60-65 m(2)/g. The electrical properties, sensitivity-synthetic conditions and operating temperatures, and selectivity of CdSnO3-based sensors were investigated. It was found that sensors had good sensitivity and selectivity to vapor of C2H5OH. Gas-sensing mechanism was studied with X-photoelectron energy spectra (XPS) and infrared (IR). (C) 2002 Elsevier Science B.V. All rights reserved.