In　this　paper,　we　demonstrate　that　the　double-step　chronoamperometry　and　chronocoulometry　techniques　are　efficient　tools　for　characterizing　the　basic　electrochromic　performance　of　WO3　films　(i.e.,　coloration/bleaching　conversion,　charge　capacity　and　coloration　efficiency).　In　combination　with　in　situ　spectro-electrochemical　study,　the　variations　in　the　optical　modulation　and　charge　capacity　of　the　WO3　film　under　different　potential　windows　were　attributed　to　different　ion　diffusion　depths　and　the　quantity　of　WO3　sites　participating　in　the　redox　reaction.　Moreover,　the　double-step　techniques　have　distinctive　advantages　for　analyzing　the　cyclic　mechanism　of　the　WO3　film.　When　the　inserted　Li+　ions　in　the　coloration　process　cannot　be　completely　extracted　from　the　film　in　the　next　bleaching　process,　these　ions　accumulate　in　the　film　upon　cycling,　leading　to　the　degradation　of　the　electrochromic　performance.　Here　the　accumulated　ions　are　referred　to　as　＂unrecoverable　ions＂.　The　abundant　formation　of　unrecoverable　ions　may　be　due　to　incomplete　reduction　of　a　portion　of　LixWO3,　which　is　caused　by　collapse　of　the　Li+　ion　diffusion　channels　in　the　deep　of　film　after　repeated　cycles.　All　these　results　support　that　the　double-step　chronoamperometry　and　chronocoulometry　techniques　have　significant　advantages　to　analyze　the　cyclic　stability　and　explore　the　degradation　mechanism　of　electrochromic　WO3　films.