Transparent ITO films were deposited on a polycarbonate substrate with RF magnetron sputtering in a pure argon(Ar) and oxygen (O2) gas atmosphere, and then post deposition electro annealed for 20 minutes in a 4×10-1Pa vacuum. Electronbombardment with an accelerating voltage of 100V increased the substrate temperature to 120oC. XRD analysis of the depositedITO films did not show any diffraction peaks, while electro annealed films indicated the growth of crystallites on the (211), (222),and (400) planes. The sheet resistance of ITO films decreased from 103 to 82Ω/□. The optical transmittance of ITO films inthe visible wavelength region increased from 85 to 87%. Observation of the work function demonstrated that the electro-annealingincreased the work function of ITO films from 4.4 to 4.6eV. The electro annealed films demonstrated a larger figure of meritof 3.0×10-3Ω-1 than that of as deposited films. Therefore, the electro annealed films had better optoelectrical performances thanas deposited ITO films.