The properties of the IZTO thin films on the glass were studied with a variation of the SiO2 buffer layer thickness. SiO2 buffer layers were deposited by plasma-enhanced chemical vapor deposition (PECVD) on the glass, and the In-Zn-Tin-Oxide (IZTO) thin films were deposited on the buffer layer by RF magnetron sputtering. All the IZTO thin films with the SiO2 buffer layer are shown to be amorphous. Optimum SiO2 buffer layer thickness was obtained through analyzing the structural, morphological, electrical, and optical properties of the IZTO thin films. As a result, the IZTO surface roughness is 0.273 nm with a sheet resistance of 25.32 Ω/sq and the average transmittance is 82.51% in the visible region, at a SiO2 buffer layer thickness of 40 nm. The result indicates that the uniformity of surface and the properties of the IZTO thin film on the glass were improved by employing the SiO2 buffer layer and the IZTO thin film can be applied well to the transparent conductive oxide for display devices.