Titanium dioxide (TiO2) thin films were deposited on fluorine tin oxide/glass and indium tin oxide/glass substrates by thermionic vacuum arc in this work. The deposited films phases were identified as anatase and rutile from X-ray Diffractions. The bandgap of the samples has been found ~ 3.0 eV. The electrochromic properties of TiO2 thin films were investigated using cyclic voltammograms, chronoamperometry and chronocoulometric studies. Electrochemical cation intercalation was promoted using 0.1 M LiClO4 in propylene carbonate. Inserted/extracted charge, diffusion coefficient, coloration efficiency, optical modulation, and reversibility was calculated. Best results were obtained for TiO2/FTO sample with 18.6 cm2/C coloration efficiency. Deposited TiO2 thin films optical and morphological studies also covered.