Islands　face　increasingly　prominent　environmental　problems　with　rapid　urbanization.　Hence,　timely　and　objective　monitoring　and　evaluation　of　island　ecology　is　of　great　significance.　This　study　took　the　Pingtan　Comprehensive　Experimental　Zone　(PZ)　in　the　east　sea　of　Fujian　Province　of　China　as　the　research　object.　Based　on　remote　sensing　technology,　four　Landsat　images　from　2007　to　2017　and　the　remote　sensing　ecological　index　(RSEI)　were　used　to　explore　the　ecological　status　and　space-time　change.　The　results　showed　that　from　2007　to　2011,　the　average　RSEI　decreased　from　0.519　to　0.506,　indicating　that　the　ecological　quality　generally　showed　a　slight　downward　trend,　mainly　due　to　large-scale　development　brought　by　the　construction;　by　2014,　although　the　ecology　of　the　original　area　improved,　the　overall　ecology　was　still　declining　with　0.502　mean　RSEI　mainly　because　of　large-scale　reclamation　projects;　by　2017,　the　average　RSEI　rebounded　to　0.523,　which　was　attributed　to　the　fact　that　ecological　construction　and　protection　were　emphasized　in　the　construction　of　PZ,　especially　in　reclamation　areas.　In　conclusion,　the　increase　of　large　area　bare　soil　will　lead　to　the　decline　of　regional　ecology,　but　the　implementation　of　scientific　ecological　planning　is　conducive　to　ecological　restoration　and　construction.