The　synthetical　decision　progress　is　an　objectless　decision　progress.　The　web-based　negotiatory　synthetical　forecasting　mode　can　be　regarded　as　an　application　type　of　GDSS　(Group　Decision　Support　System).　The　paper　presents　an　improved　common　web-based　negotiatory　synthetical　forecasting　Delphi　Model.　It　gets　a　consistent　decision　conclusion　through　multi-rounded,　multi-tiered　and　multi-modeled　cooperative　progress.　The　J2EE　architecture　is　a　realization　of　the　MVC　(Model-View-Controller)　architecture.　According　to　the　characters　of　the　improved　common　web-based　negotiatory　synthetical　forecasting　Delphi　Model　and　the　improved　J2EE　architecture,　architecture　of　web-based　negotiatory　synthetical　earthquake　forecasting　GDSS　using　J2EE　technique　is　presented　on　background　of　earthquake　synthetical　forecasting.　The　architecture　has　already　been　applied　in　a　real　world　system.　The　Entity　Bean　is　replaced　with　O/R　Mapping　tools　+　Java　Beans　so　that　the　running　speed　of　the　software　can　remain　in　a　reasonable　level　without　loosing　the　flexibility　and　reliability　of　the　J2EE　architecture.