Tungsten　trioxide　(WO3)　nanostructures　were　synthesized　by　a　hydrothermal　method,　and　the　influence　of　essential　hydrothermal　conditions,　temperature　and　time,　on　their　crystal　structure,　morphology　and　visible-light　driven　photocatalysis　was　studied.　The　hydrothermal　temperature　was　varied　from　120　°C　to　200　°C,　and　the　hydrothermal　time　changed　from　12　h　to　32　h.　The　crystal　structure,　morphology　and　photocatalytic　performance　of　WO3　nanostructures　were　characterized　by　XRD,　SEM　and　UV-Vis.　The　crystal　structure　of　WO3　nanostructure　was　triclinic　phase　and　their　morphology　was　mainly　one　dimensional　nanorods.　Methylene　blue　was　used　as　the　target　to　evaluate　their　photocatalytic　performance　under　visible　light　(λ＞420　nm).　The　photocatalytic　results　suggest　the　suitable　hydrothermal　conditions　to　synthesize　WO3　nanostructures　for　the　wastewater　treatment　application.　©　2020　Trans　Tech　Publications　Ltd,　Switzerland.