The　fluorescence　technology　was　applied　to　study　of　the　magnetic　field　effect　on　the　rate　of　hydroxyl　radical　center　dot　OH　formation　produced　on　the　surface　of　Pt/TiO2　film　in　aerated　NaOH　solution,　using　tereplithalic　acid　as　the　hydroxyl　radical　capturer.　Compared　with　the　normal　photocatalytic　reaction,　the　results　showed　that　in　the　presence　of　external　magnetic　field　the　formation　rate　of　surface　hydroxyl　radical　was　increased　by　11.7%.