The desertification or land degradation is a phenomenon that has been occurring in many parts of the planet. This process has been accompanied by climatic factors and socio-ecological, and in the Northeast of Brazil is considered a phenomenon resulting from human intervention over the environment. This work was proposition estimate the amount of live biomass lost in the city of Picuí - PB from the multitemporal analysis of vegetation cover using satellite images. For both GIS and Remote Sensing techniques were used, with the purpose of calculate soil degradation over the past three decades, and calculate the NDVI, SAVI and IAF vegetation index, to estimate the amount of living biomass lost over in the period studied. As a result, it was verified that the city has about 30% of its land in degradation level ranging from grave and very grave, and that the living biomass decreased by about 20% in these past three decades, coming to present about 49% of green area, and about 51% of degraded areas considered, a fact that has been proven through technical visits, which identificated that the areas are degraded by vegetal extraction of wood, mining and agriculture.