The　advent　of　the　energy　Internet　(EI)　has　dramatically　changed　the　energy　model　of　today＇s　world.　Despite　scholars　have　done　a　lot　of　research　on　energy　Internet,　few　articles　have　been　written　to　evaluate　its　CO2　emission　reduction.　In　order　to　fill　the　vacancy,　system　dynamics　(SD)　is　used　to　set　up　the　dynamic　assessment　model　of　CO2　emission　reduction　of　regional　energy　Internet.　To　illustrate　the　effectiveness　of　the　model,　we　take　the　energy　Internet　in　Yanqing　district　of　Beijing　as　an　example　for　simulation.　The　results　show　that　the　total　CO2　emission　reduction　of　this　energy　Internet　will　reach　5056.82　tons　in　2019,　and　the　emission　reduction　will　continue　to　increase　in　the　following　years,　the　total　amount　of　CO2　emission　reduction　peaked　at　13384.80　tons　in　2030.　We　conclude:　(1)　The　CO2　emission　reduction　dynamic　assessment　model　established　in　this　paper　has　a　strong　versatility　and　can　be　applied　to　any　built　or　planned　energy　Internet.　(2)　Energy　Internet　has　a　good　long　term　effect　in　emission　reduction.　(3)　The　emission　reduction　of　the　supply　side　is　the　most　obvious;　the　user　side　has　the　greatest　potential　for　emission　reduction,　while　the　contribution　of　the　transmission　side　to　emissions　reduction　is　the　most　stable.　The　innovation　points　of　this　paper　mainly　include:　(1)　we　put　forward　and　solve　the　dynamic　assessment　of　carbon　emission　reduction　on　the　energy　Internet　for　the　first　time.　(2)　We　establish　a　dynamic　assessment　model　of　CO2　emission　reduction　in　the　energy　Internet　based　on　system　dynamics.　(3)　We　quantitatively　analyze　the　emission　reduction　contribution　of　the　supply　side,　transmission　side　and　user　side　of　the　energy　Internet.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.