1,8-naphthalene　anhydride　(1,8-NA)　is　a　common　polycyclic　aromatic　hydrocarbons　(PAHs)　which　are　the　most　important　light　absorbed-organic　aerosols　(BrC)　in　atmospheric.　1,8-NA　can　generate　different　ROSs　(.OH,　.O2-　,　H2O2,　1O2)　under　the　visible　light　irradiation.　According　to　the　results　of　DFT　simulation　and　band　structure　analysis,　1,8-NA　has　the　semiconductor　characteristic,　and　the　electrons　of　it　can　be　excited　from　acid　anhydride　part　to　naphthalene　ring　part.　Meanwhile,　a　built-in　electric　field　exists　between　the　acid　anhydride　and　the　naphthalene　ring　because　of　the　molecular　polarization　of　1,8-NA.　This　electric　field　could　promote　the　separation　and　migration　of　carriers.　Therefore,　electrons　can　easily　be　transferred　to　O2　and　produce　ROS.　The　properties　and　mechanism　of　photocatalytic　O2　activation　by　atmospheric　aerosol　component　1,　8-NA　were　studied　for　the　first　time,　which　provided　good　support　for　further　understanding　of　atmospheric　photochemical　mechanism.