A new high quality transparent conductive thin film In O: Mo (IMO) was prepared by conventional thermal reactive evaporation at the substrate temperature of approximately 350 C. From X-ray photoelectron spectroscopy XPS and X-ray diffraction (XRD) analysis of IMO films, it was confirmed that Mo6+ substituted In6+ without changing the cubic bixbyite structure of In2O3 and there were no new compounds in IMO as well. One atom of dopant contributes with more electrons to the electrical conductivity and at the same carrier concentration there is fewer dopant in IMO than in other doped oxides. So, the IMO film exhibits simultaneously higher values of Hall mobility, electric conductivity, visible light transmittance, infrared reflectance and plasma wavelength. An electrical resistivity as low as 1.7×0-4Ωcm was obtained, while the infrared reflectance above 4μm and the average total visible light transmittance of the IMO film plus the glass substrate were both over 80%, and the plasma wavelength was at approximately 2.2μm. IMO is more suitable for the energy efficient windows used in cold climates or even for optoelectronic device applications. © 2001 Elsevier Science B. V. All rights reserved.