Xiong＇an　New　Area　is　a　state-level　development　area　established　in　2017　and　many　buildings　and　roads　have　been　developed　in　the　area　since　then.　Nevertheless,　there　were　no　researches　on　the　ecological　changes　of　the　area　caused　by　the　development.　To　meet　this　requirement,　two　Landsat　8　images　in　2017　and　2020　were　selected　in　this　paper　to　study　the　ecological　effects　of　the　areal　development.　The　2017　image　was　used　to　represent　the　period　before　the　development　of　the　Xiong＇an　New　Area,　whereas　the　2020　image　was　to　represent　the　period　after　three-year　development.　The　development-induced　main　land　cover　changes　in　the　Xiong＇an　New　Area　were　revealed　using　remote　sensing　techniques.　The　remote　sensing　based　ecological　index　(RSEI)　was　used　to　evaluate　the　ecological　changes　of　the　new　area　in　the　period　due　to　the　land　cover　changes.　The　results　showed　that　(1)　the　development　of　the　Xiong＇an　New　Area　from　2017　to　2020　has　caused　an　increase　of　60.　01　km2　in　built-up　land,　an　increase　of　8.　95　km2　in　open　water,　and　a　decrease　of　69.　29　km2　in　vegetation.　The　development　of　the　new　area　is　currently　concentrated　in　Rongcheng　and　Xiongxian　counties,　while　Anxin　county　is　less　developed.　(2)　The　development-induced　ecological　change　in　the　period　is　characterized　by　the　fact　that　the　ecologically　improved　area　is　larger　than　the　degraded　area,　and　the　area　proportion　of　remote　sensing　based　ecological　index　(RSEI)　above　good　grade　rose　slightly　during　the　period.　Therefore,　the　overall　ecological　quality　of　the　new　area　has　increased　slightly　in　the　three　years,　showing　by　the　increase　of　the　mean　RSEI　from　0.668　in　2017　to　0.677　in　2020.　Nevertheless,　the　presentations　of　the　three　counties　were　different.　The　mean　RSEIs　of　Xiongxian　and　Anxin　counties　have　increased,　while　the　mean　RSEI　of　Rongcheng　County　has　decreased　slightly.　(3)　The　improvement　of　ecological　quality　in　the　Xiong＇an　New　Area　mainly　benefited　from　its　new　planning　thought　that　insisted　on　ecological　priority　and　green　sustainable　development,　as　well　as　the　implementation　of　several　projects　to　improve　ecological　quality,　such　as　the　Qiannian-xiu-lin　forest　project　and　the　returning　of　cultivated　land　to　water　project　that　insure　high　blue　and　green　proportions　in　the　new　area.　©　2023　Science　Press.　All　rights　reserved.