Nb2O5 films were prepared successfully by DC reactive sputtering process. The relationships among structural, morphological and electrochromic properties were studied using XRD, AFM, AES and cyclic voltammograms. Results show that the films deposited on heated substrates are composed of columnar TT-Nb2O5 microcrystalline with many grain-to-grain boundaries. These structural characteristics provide films strong electrochemical stability, high Li+ insertion/extraction reversibility and good electrochromic properties. DC reactive sputtered Nb2O5 films are colorless in bleached state and brownish gray in colored state and may be a promising candidate for the application in electrochromic devices. (C) 2002 Elsevier Science B.V. All rights reserved.