Niobium pentoxide is one of the promising materials in electrochromic applications. In this study we investigate electrochromic properties of sol-get dip coated undoped and ZrO2 doped Nb2O5 thin films. Nb2O5 sol was mixed with 5 vol. % and 10 vol. % of ZrO2 sol. Coated samples were subjected to heat treatment at 550degreesC for crystallization. Electrochrornic and optical properties of these films were investigated by using cyclic voltammeter and spectrophotometer. It has been observed from cyclic voltammetry measurements heat treatment causes a deterioration in the charge density of the pure Nb2O5 films.