WebGIS is a key direction of GIS development in recent years, yet there is no explicit definition of WebGIS. After some reviews of the development process of Geographical Information sharing through Internet and the development process of traditional GIS, this paper presents a view that geographical data (especially vector format data) visualization and spatial analysis function are the vital character of WebGIS. Common Internet browser is suit for information retrieve by text keywords and Image data display, yet it is not suit for geographical information organization, retrieve and analysis. Based on the Internet's Browser/Server architecture, this article puts forward an idea of WebGIS agent server based on the GIS metadata and its management system. WebGIS agent server provides temporal spatial attribute data analysis and fusion function, and it is more powerful and convenient for geographical Information application purpose. WebGIS includes WebGIS data server, WebGIS agent server and WebGIS Browser. We use java programming language and relational database as the platform to realize this architecture. First we convert all the spatial and non spatial information into relational database, using ODBC to manage those data. JAVA and ODBC are connected through ODBC/JDBC bridge. WebGIS browser builds topological relationship and geographical object in real time by spatial index when they visit WebGIS data server. Finally, we establish a prototype model of Jing Jiu Railway Corrida Region Investment Environment Information System based on the analysis of the connotation, function, architecture and technical solution of WebGIS discussed above. It's a concrete example of WebGIS. Though it is simple and incomplete, it provides the base for further discussion.