The　porous　WO3/reduced　graphene　oxide　(rGO)　composite　films　are　prepared　on　indium-tin　oxide　(ITO)　glass　by　sol-gel　method.　The　mixture　sol　combines　peroxotungstic　acid　solution　with　rGO　dispersion　reduced　by　ethylene　glycol　(EG).　The　excessive　EG　and　other　organic　additives　are　subsequently　removed　by　annealing,　which　leads　to　the　formation　of　porous　structure.　Compared　with　pure　WO3　film,　WO3/rGO　composite　film　shows　improved　electrochromic　performance　because　of　enhanced　double　insertion/extraction　of　ions　and　electrons.　It　realizes　a　large　optical　modulation　(64.2　%　at　633　nm),　fast　switching　speed　(9.5　s　for　coloration　and　4.5　s　for　bleaching),　good　cycling　stability　as　well　as　reversibility.