ITO/TiO2 films were deposited by RF magnetron sputtering on glass substrates and then the effect of vacuum annealing on the structural, optical and electrical properties of the films was investigated. The structural, optical and electrical properties are strongly related to annealing temperature. The films annealed at 300℃ showed a grain size of 40.9 nm, which was larger than as-deposited amorphous films. The optical transmittance in the visible wavelength region also increased, while the electrical resistivity decreased. The ITO/TiO2 films annealed at 300℃ showed the highest optical transmittance of 81% and also showed the lowest electrical resistivity of 3.05×10-4 Ω㎝ in this study.