In　view　of　the　accumulative　circulation　effect　and　structural　synergistic　evolution　of　energy　metabolism　in　cities,a　model　for　urban　energy　metabolism　system　is　established　based　on　ecological　network.The　accumulative　circulation　effect　of　energy　in　urban　energy　activities　is　described　and　measured　by　using　reachable　matrix.On　this　basis,the　key　factors　in　urban　energy　metabolism　system　that　influence　the　synergistic　evolution　are　further　identified　and　the　dominant　elements　in　urban　energy　metabolism　path　are　calculated　based　on　Haken＇s　model.Finally,the　empirical　test　is　carried　out　in　Beijing.The　results　show　that　the　use　intensity　of　coal　in　the　primary　and　secondary　industries　and　the　use　intensity　of　natural　gas　in　the　secondary　industry　are　the　key　factors　affecting　the　orderly　evolution　of　the　energy　metabolism　system　in　Beijing.Among　these　factors,the　use　intensity　of　coal　in　the　secondary　industry　is　an　order　parameter　and　plays　a　leading　role　in　the　synergistic　evolution　of　the　energy　metabolism　system　in　Beijing.　©　2018,　China　National　Chemical　Information　Center.　All　right　reserved.