Based on plugin technology of .Net Framework,the C# and ArcEngine10.0 components were combined to design and develop the Green Subclass Management System of Swath Forest (GSMSSF) in Wuhan outer-ring expressway.The GSMSSF system fulfilled the subclass information storage temporally and spatially,provided the query,analysis and forecast function to all trees in plugin mode.Under this mode,all functions or modules in GSMSSF are treated as plugin coupling with the system framework,which is convenient to be expanded or upgraded.