Abstract: With an introduction of the basic principles of geographic information system (GIS), the paper discussed its application in petroleum exploration and development. A complete GIS can provide geologists a powerful tool for the inquiry, collection, analysis, display, modification and drawing of various data of hydrocarbon exploration and development. Especially, the application of 3-D visualization technigue will get a deeper understanding of geometries and characteristics of reservoirs, and hence improve the estimation ofreserves and increase the success ratio of prospection drilling.