The thin film deposition system using ultrasonic nebulization was adopted in this study. SnCl4.5H2O, SbCl3, and TaCl5 were used as solutes. Ethanol was used as the solvent. Solutions of different Sn4+ concentration, Sb concentration (Sb/Sn atomic ratio) in Sn, and Ta concentration (Ta/Sn atomic ratio) in Sn were mixed. The mist was generated from a solution by the agitation of an ultrasonic device operating at about 1.65MHz. The mist was carried to the heated substrate (corning 7059 glass) by the flow of nitrogen gas so that it was decomposed by heat. SnO2-x films were deposited on the substrate due to the pyrolysis reaction. The experiment included six series: Sn4+ concentration series, Sb-doping series, temperature series, Ta-doping series, aging time series and nebulization rate series. SnO2-x films were analyzed by XRD, UV-Visible, SEM, and Hall-measurement. The optimum deposition conditions were obtained through analyses of these six series. The film deposition rate of nonaged solution was faster than aged solution. When the nebulization rate of solution was 1.6 ml/min, the resistivity of undoped SnO2 film obtained with the substrate kept at 450 oC is 2.364¡Ñ10-2£[-cm and the maximum transmittance of the visible light is 78.7%. When Sb/Sn atomic ratio in the solution was 2%, the resistivity of Sb doped SnO2 film obtained with the substrate kept at 525 oC is 2.77¡Ñ10-3£[-cm and the maximum transmittance of the visible light is 71% . When Ta/Sn atomic ratio in the solution was 0.1%, the resistivity of Ta doped SnO2 film obtained with the substrate kept at 450 oC is 3.917¡Ñ10-2£[-cm and the maximum transmittance of the visible light is 85% In this study, the electro-optical properties of Sb and Ta doped SnO2 thin films derived from an ultrasonic nebulization process were reported and discussed carefully through film characterizations.