Abstract: Abstract: The 1:500000 geological map database of China was developed with the China-made software MAPGIS 5.0 as the basic platform and the appended maps (1:500000) of regional geology of all the provinces, autonomous regions and municipalities and the 1:200000 geological map of the Hong Kong Special Administrative Region as the basic data. The geological map was compiled by using new theories and ideas on modern geology, stratigraphy and petrology and new methods of presentation and according to the lithostratigraphic units, hierarchical units of granites and time plus lithology for intrusive rocks. The database was composed of the digital geological map database and geographic base map database. The retrieval can be made arbitrarily according to any space scope, different scales, different projection methods and different geological and geographic content, and one can retrieve one item or multiple items. Through retrieval a complete geological map with the legend and ornaments is produced automatically.