[ $In_2O_3-ZnO(IZO)$ ] and $In_2O_3-ZnO-SnO_2(IZTO)$ thin films were prepared on EAGLE 2000 glass webs in a Ar gas by RF-Magnetron sputtering. Electrical resistivity and optical transmittance of the films were investigated. IZO, IZTO film showed excellent optical transmittance of 85 % at the visible $400{sim}$780 nm wavelength. Electrical properties of IZO film have $6.50{ imes}10^{-4}{Omega}cm$ (95 $In_2O_3$ : 5 ZnO wt.%) and $5.20{ imes}10^{-4}{Omega}cm$ (90 : 10 wt.%), IZTO film have $8.00{ imes}10^{-4}{Omega}cm$ (90 $In_2O_3$ : 3 ZnO : 7 $SnO_2$ wt.%) and $6.50{ imes}10^{-4}{Omega}cm$ (90 : 7 : 3 wt.%). Substitution of SnO to ZnO in ITO films showed slightly lower electrical conductivity than ITO film but showed similar optical transmittance.