The　photocatalytic　degradation　of　bromomethane　in　airstreams　was　studied　over　the　TiO2　catalysts　prepared　by　sol-gel　method.　The　influence　of　calcination　temperature,　reaction　temperature,　the　residual　NO;　in　catalyst　and　water　vapor　on　the　structure　of　catalysts　and　their　photocatalytic　performance　was　examined　by　means　of　X-ray　diffraction　technique,　Nz　sorption　analysis　with　BET　method,　FTIR　spectroscopy　and　photocatalytic　activity　measurement.　The　results　showed　that　the　photocatalytic　decomposition　of　CH3Br　followed　first-order　kinetics,　and　the　apparent　activation　energy　was　determined　to　be　13.7　kJ/mol.　The　distinct　deactivation　of　TiO2　catalysts　for　the　photocatalytic　oxidation　of　bromomethane　was　observed　in　the　initial　period　of　reaction.　Some　factors　such　as　high　calcination　temperature,　the　residual　NOB　and　water　vapor　in　the　feed　stream　decreased　the　photocatalytic　activity　of　TiO2　catalysts.　However,　the　reactivity　of　bromomethane　is　greatly　enhanced　at　increasing　reaction　temperatures.　The　effect　of　raising　reaction　temperature　has　been　ascribed　to　decreasing　adsorption　of　water.