The　Minjiang　River　Estuary　Wetlands　are　one　of　the　most　important　coastal　wetlands　in　China.　The　wetlands　in　this　drainage　basin　possess　the　specific　features　in　terms　of　types　and　quantity　of　the　waterfowls,　and　are　important　habitats　for　the　migratory　birds　that　migrate　seasonally　from　East　Asia　to　Australasia.　Therefore,　it　is　significant　to　enhance　the　management　of　the　wetlands.　To　manage　and　protect　the　wetlands　in　a　more　scientific　and　rational　way,　many　countries　and　regions　have　set　up　a　special　wetland　information　management　and　supporting　system　using　geography　information　system　(GIS)　technology.　The　component　-based　GIS　system　(ComGIS)　has　enormous　advantages　in　seamless　integration　and　the　flexibility　of　the　system.　It　stands　for　the　development　trend　of　GIS.　ComGIS　is　a　perfect　way　to　make　GIS　a　popular　tool　for　both　professional　and　non-professional　people.　Applying　the　COM　technology,　a　specific　GIS　system　named　MJWIS　for　monitoring　and　managing　of　the　Minjiang　River　Estuary　Wetlands　has　been　developed　in　the　research　based　on　mathematical　and　ecological　theories.　MJWIS　is　programmed　by　Microsoft　Visual　Basic　6.0　software　based　on　MapObjects2.0　that　is　a　GIS　component　of　American　ESRI　Company.　It　is　composed　of　3　layers:　basic　information　layer,　function　module　layer　and　information　expressing　layer.　The　wetland　system　provides　the　following　functions:　to　edit　and　browse　data,　to　query　data,　spatial　analysis,　to　make　thematic　maps,　to　print　report　form,　graphics　tools,　wetland　ecologic　analysis,　wetland　dynamic　change　analysis,　and　so　on.　Then　some　detail　about　the　wetland　system　database　build-up　and　the　key　technologies　of　the　system　designing　and　programming　were　discussed　in　the　paper.　The　key　technologies　include:　acquiring　and　updating　the　wetland　data,　standardizing　the　wetland　data,　mapping　wetland　change,　and　analysis　model　of　wetland　change.　At　last,　the　classified　images　and　its　vector　diagram　of　Minjiang　River　Estuary　Wetlands　were　made　by　remote　sensing　and　GIS　software　using　Landsat　TM　Satellite　Data　taken　in　1986,　1994　and　2000,　and　the　wetland　dynamic　change　from　1986　to　2000　was　analyzed　based　on　MJWIS.　The　results　showed　that　using　the　ComGIS　technology,　the　wetland　system＇s　main　function　module　was　divided　into　several　controls,　and　every　control　fulfilled　different　function　like　a　heap　of　building　block.　Therefore,　the　wetland　system　was　established　effectively　by　some　controls＇　combination　according　to　demands,　and　could　be　maintained,　extended　and　reused　effectively　in　the　future.　The　application　to　the　Minjiang　River　Estuary　Wetlands　showed　that　the　system　could　provide　visual　information　and　a　vivid　way　to　analyze　wetland　change.　It　enhanced　the　management　of　the　Minjiang　River　Estuary　Wetlands.　And　the　analysis　results　indicated　that　the　human　activities　have　become　the　main　cause　of　the　wetland　change,　with　the　development　of　society　and　economy　during　the　period　from　1986　to　2000.　To　perfect　the　system,　a　new　component　called　ArcEngine　of　ESRI　Company　would　be　used　to　specially　enhance　the　raster　analysis　function　in　the　future.