The software of free code Quantum GIS (QGIS) is a friendly tool for its application in diverse activities of territorial planning, in the present work its potential of use in processes of ecological regionalization is demonstrated for the Cuenca Cienaga de la Virgen en Cartagena de Indias (Colombia) and municipal area involved. In addition to enabling a mechanism of democratization of the Geographic Information Systems, QGIS allowed to generate cartographies and enable the hierarchical classification of the ecosystems identified as Unidades Ecologicas de Gestion (UEG) for the Basin under study. At the ecodistrict scale, 3 UEG are identified and at the 9 UEG ecosection scale; process based on the ecosystem approach. Keywords: Quantum, SIG, Cuenca Cienaga de la Virgen.