Abstract: The bovine beef cattle in Brazil are predominantly extensive, what turns great natural areas into grazing. An alternative to reduce the occupied area is to intensify cattle creation, increasing productivity, but it demands a bigger use of water and animals supplements, that are based principally in soy. The deviation of high quantities of water to economic activities can cause a shortage of it on the future, and intensifies cattle raising could mean an increase of soy production. This work realized a study using a mathematical model in fuzzy language to accomplish a simulation of two Brazilian areas in risk because of beef cattle expansion: Pantanal and Legal Amazon. The results indicate that the intensification strongly decreases the grazing areas, what theoretically reduces deforestation. However, analyzing the socio-economical context , the intensification doesn\'t solve the deforestation problem, because in Legal Amazon, it revolves around the estate speculation, not linked to beef production, and in Pantanal, the extensive beef cattle have caused less impact on environment, because it is developed by small creators that produce without going beyond ecosystem capacity. Besides, simulations indicate that intensification means strong pressure on hydrics sources.