Titanium dioxide (TiO2) thin films were prepared on silicon substrates by plasma-enhanced chemical vapor deposition (PECVD) using Ti(O-i-C3H7)(4) and oxygen. PECVD of TiO2 films has been evaluated with various process parameters. The characteristics of films were investigated by X-ray diffraction, scanning electron microscopy, TG/DTA, FTIR, UV/visible spectroscopy and Auger electron spectroscopy. Typical as-deposited film was amorphous and transparent with a refractive index of 2.05. As the deposition time increased, surface morphology became coarser, and structure was transformed from amorphous to mixtures of amorphous and crystal. As-deposited amorphous TiO2 films had a dielectric constant of 13.7 and flat-band voltage of -1.3 V. The effects of post-treatment through N-2 or O-2 plasma on the electrical properties of as-deposited films were evaluated. Electrical properties could be enhanced by O-2 plasma treatment.