| This twenty-first century is a time belonging to information technologies and the Internet as well. As the Internet grows rapidly, GIS expands its application domain from the desktop to the Internet. However, we have to face this reality: traditional web languages can only describe information limited to text and bitmap, but show their born limitations and shortages, which cause the difficulty in displaying and publishing spatial vector data on the web and further prevent GIS from applying in the Web.SVG, a scalable vector graphics language description specification based on XML, is developed by W3C organization for rapid Internet applications, which can meet demands required when spatial data are on a graphic display in GIS.Based on the SVG specification designed by W3C, a hybrid map publishing system is constructed, by using our extended SVG as the format of geographical data used for storage, delivery and rendering and also integrating current map publishing technologies. The main content can be divided into parts as follows:1 Concepts and characteristics of WebGIS are summarized and then special focus is putto introduce problems met with when information published in WebGIS. 2 Current map publishing technologies are compared and analyzed, by probing into theadvantages and disadvantages of each technology.3 SVG as a vector graphics standard based on XML, is deeply studied, including its concept, its characteristics, its advantages for web applications and also its application in GIS. Based on the above study, an idea is proposed for extending SVG markers, map symbols based on SVG are also designed, and methods for organizing and encoding geographical data based on SVG are introduced as well. 4, A hybrid map publishing system is built by using current technologies in WebGIS and taking our extended SVG as the data format for organizing and delivering geographical data, later its implementation is discussed in detail, and finally an example is made by using WuHan University digital map.
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