Tungsten　trioxide　(WO3)　nanostructures　were　synthesized　by　a　simple　hydrothermal　method.　The　morphology　of　WO3　nanostructures　can　be　varied　by　adding　inorganic　ions　from　alkali　metal　salts.　The　effect　of　inorganic　ions　on　the　microstructure　and　visible-light-driven　photocatalytic　activity　was　characterized　via　X-ray　diffraction　(XRD),　scanning　electron　microscopy　(SEM),　X-ray　photoelectron　spectroscopy　(XPS),　and　UV-vis　spectroscopy.　Methylene　blue　(MB)　photodegradation　experiments　showed　that　the　one-dimensional　(1D)　WO3　nanorods　prepared　by　the　aid　of　potassium　sulfate　exhibited　the　highest　photocatalytic　efficiency　(96.4%　in　2.5　h)　under　visible　light　irradiation.　It　is　deduced　that　the　excellent　photocatalytic　property　of　1D　WO3　nanorods　was　mainly　attributed　to　the　efficient　charge　transfer　capability,　which　is　promising　for　practical　applications　in　environmental　remediation.