1）Department of Traffic Engineering，Sichuan College of Architectural Technology，Deyang 618000 2）School of Architectural and Surveying & Mapping Engineering，Jiangxi University of Science and Technology，Ganzhou 341000
Abstract The Geography Markup Language （GML）is an XML grammar for expressing geographical features，the best way to store XML data is native database system （XND）.Thus through extreme NXD to implement GML database system （NGD）is a good way to implement GML database system.The native GML database system was defined combininy native XML database and spatial database system and studied its store grain size，logical model and frame of system were studied.At last，by use of Java language the store and index modules of the designed native GML database system were is implemented.Through the experiment it is proved that the efficiency of native GML database is higher than that of the spatial database system.
