Nanoporous　tungsten　oxide　films　were　synthesized　by　an　anodic　oxidation　process　in　aqueous　NaF/HF　electrolytes.　The　tungsten　films　were　deposited　by　the　radio　frequency　magnetron　sputtering　method　on　sapphire　substrates,　and　the　anodic　oxidation　process　was　conducted　in　a　dual-electrode　reaction　chamber　with　graphite　electrode.　The　effects　of　processing　parameters　(anodic　voltage,　time,　temperature,　and　the　operation　distance)　on　the　morphology　and　porosity　of　the　synthesized　films　were　investigated　experimentally.　The　samples　were　characterized　by　x-ray　diffraction　and　scanning　electron　microscopy.　The　results　showed　that　the　pore　diameter　and　porosity　increased　gradually　with　increasing　anodic　voltage,　whereas　the　＂wall＂　of　the　pore　was　subjected　to　electric　breakdown　at　60　V,　and　the　pore　diameter　and　porosity　decreased.　The　pore　diameter　and　porosity　showed　an　early　increased　and　later　decreased　state　as　the　operation　time　and　distance　are　increased.　The　sensitive　response　in　the　resistive　method　is　reaction-dominated　type　and　is　exhibited　as　a　linear　relationship　as　a　function　of　hydrogen　gas　concentration.　The　response　toward　500　ppm　hydrogen　in　air　is　up　to　15.1　with　a　response　time　of　10　min　at　200　degrees　C.