The generation and disclosure of information on water resources is an important strategy to facilitate the implementation of basin master plans. Every area of land, however small, is integrated to a watershed, so the present study aims at mapping the use and occupation of soil at the Pajeú river basin, from unsupervised classification of satellite images Landsat 5 in system software geographic information, ArcGIS 10.1 where it was possible to identify the main soil types and their respective levels of environmental fragility