China　is　currently　undergoing　rapid　urbanization,　which　inevitably　brings　negative　impacts　on　the　country＇s　eco-environment.　The　degradation　of　urban　ecological　quality　is　one　of　the　most　serious　problems.　It　appears　urgent　for　the　country　to　monitor　the　dynamics　of　the　ecological　conditions　timely　and　fast.　In　this　paper,　using　Landsat　imagery,　we　evaluated　ecological　environment　changes　of　the　Hangzhou　area　from　1989　to　2010　with　a　recently-proposed　remote　sensing　based　ecological　index(RSEI).　The　results　show　that　the　overall　ecological　quality　of　Hangzhou　had　asignificant　decline　accompanied　with　the　expansion　of　urban　built-up　area.　The　mean　values　of　RSEI　fell　to　0.609　in　2000　and　0.555　in　2010　while　it　was　0.625　in　1989,　and　the　proportion　of　high-grade　RSEI　area　also　fell　from　66.57%　in　1989　to　61.72%　in　2000　and　then　to　40.04%　in　2010.　The　spatial　analysis　of　the　ecological　change　of　Hangzhou　reveals　that　the　ecological　quality　has　become　worse　in　the　newly-developed　urban　sub-center　areas.　In　spite　of　this,　the　ecological　condition　in　the　old　city　center　area　has　been　improved　The　most　crucial　factor　which　leads　to　the　decline　of　the　ecological　quality　of　Hangzhou　during　the　study　period　is　the　fast　expansion　of　the　built-up　land　in　Hangzhou.　©,　2015,　The　Editorial　Board　of　Journal　of　Basic　Science　and　Engineering.　All　right　reserved.