The 1:5000000 International Geological Map of Asia (IGMA5000) under the aegis of the Commission for the Geological Map of the World (CGMW) is a cooperative project which involves more than 100 geologists from 4 subcommissions of CGMW as well as geological surveys and institutions of 20 Asian and European countries. IGMA5000 is the first digital Asian geological map built on the ArcGIS platform and compiled in accordance with international standards and also the first map that displays the off-shore and on-shore geology within the map area, and therefore the compilation of the map is extremely arduous and challenging. The map area covers whole Asia and its adjacent regions from the Alps in the west to the Mariana Trench in the east, and from the Arctic Ocean in the north to the Java Trench in the south. The amount of data in the spatial database is 2.14 GB. The paper introduced the basic construction of ICMA5000. Its successful completion will surely lay a solid foundation for researches on the tectonics, metallogeny, resources and geological environment of Asia.