Metallosupramolecular coordination polyelectrolyte,Fe(Ⅱ)-metalloviologen(FEN),was prepared by the reaction of Fe(Ⅱ) with a novel bisterpyridine ligand.As active components,FENs could be assembled into electrochromic multilayer films with negative charged polystyrene sulfate(PSS) by the sequential deposition layer-by-layer technique.Numerous analytical instruments,such as UV-Vis spectroscopy,atomic force microscopy(AFM),tunneling electron microscopy(TEM),zeta-potential measurement and electrochemical measurement have been utilized to characterize their morphology,optical and electrochromic properties.It has been observed that as-prepared films exhibited multi-colour changes by triggering with different potentials.However,the low optical contrast of multilayer films would limit their further applications.In order to overcome this problem,semiconductor TiO2 nanoparticles(TiO2) were incorporated into FEN multilayers by layer-by-layer approach.By carefully optimizing the film structure,as-resulted hybrid films containing FEN,TiO2 and PSS exhibited high optical contrast,suitable response time and long-term stability.Such hybrid films should be promising candidatcs to meet the requirements for developing flexible displays and electrochromic devices.