Underwater　video　intelligent　monitoring　system　extracts　moving　objects　in　a　complex　and　dynamic　scene　with　the　impact　of　wave,　illumination　changes　and　reflection,　while　needs　real-time　character.　To　solve　these　situations,　underwater　moving　object　detection　algorithm　based　on　codebook　model　was　presented.　The　algorithm　creates　a　background　codebook　for　each　pixel　according　to　color　distortion　and　brightness　distortion,　and　then　extracts　the　moving　objects　using　the　current　pixel　to　match　with　code　words　in　the　codebook.　To　adapt　the　complex　changes　of　scene,　the　algorithm　updates　adaptively　the　background　codebook　model　using　the　sample　value　of　pixel　of　current　image.　The　experiments　show　that　the　algorithm　can　extract　the　complete　moving　objects　by　overcoming　the　impact　of　underwater　environment　and　inhibiting　noise.　And　the　algorithm　has　perfect　real-time　character.　©　2013　IEEE.