Organophosphate　pesticides　(OPs)　are　among　the　most　widely　used　synthetic　chemicals　for　the　control　of　a　wide　variety　of　pests,　and　reactive　oxygen　species　(ROS)　caused　by　OPs　may　be　involved　in　the　toxicity　of　various　pesticides.　Previous　studies　have　demonstrated　that　a　reactivation　of　latent　Epstein-Barr　virus　(EBV)　could　be　induced　by　oxidative　stress.　In　this　study,　we　investigated　whether　OPs　could　reactivate　EBV　through　ROS　accumulation.　The　Raji　cells　were　treated　with　chlorpyrifos　(CPF),　one　of　the　most　commonly　used　OPs.　Oxidative　stress　indicators　and　the　expression　of　the　EBV　immediate-early　gene　BZLF-1　were　determined　after　CPF　treatment.　Our　results　show　that　CPF　induces　oxidative　stress　as　evidenced　by　decreased　malondialdehyde　(MDA)　level,　accompanied　by　an　increase　in　ROS　production,　DNA　damage,　glutathione　(GSH)　level,　and　superoxide　dismutase　(SOD)　and　catalase　(CAT)　activity.　Moreover,　CPF　treatment　significantly　enhances　the　expression　of　BZLF-1,　and　the　increased　BZLF-1　expression　was　ameliorated　by　N-acetylcysteine　(NAC)　incubation.　These　results　suggest　that　OPs　could　contribute　to　the　reactivation　of　the　EBV　lytic　cycle　through　ROS　induction,　a　process　that　may　play　an　important　role　in　the　development　of　EBV-associated　diseases.