Geographic Information System is a system which is composed by six elemements: People, hardware, software, data, process and network. The system could manage data by maps and data base. Maps present spatial data and can combine many layers. By this way, the relationship between species and environment factors can be analyzed. The results are vegetation maps, distribution maps.... The information of vegetation cover, mammal. bird and plant... are stored in the data base system. The information includes classification system, common name. scientific name, status and other attributes... The data base system is linked with maps and exporting to thematic maps. GIS could manage large data base of biology and being useful for biodiversity conservation and management. The paper present the application of GIS in data management of the Xuan Lien protected area- Thuong Xuan district, Thanh Hoa province.