Abstract in English:PARECIS Plateau in the State of Mato Grosso has been submitted to an intense process of occupation for the last thirty years. Through this work a temporal analysis is done on the borders of Nambikwara and Enawene-Nawê which are two of several other indian reservations that are distributed over the Parecis Plateau. The study analyses the spatial distribution of the reservation boundaries and the expanding nearer cropfields. TM-LANDSAT images collected in June of 1984 and May/June of 1997 are the main data support. The general procedures included: digitizing the reservation bounds; conforming cartographic bases and projections; registering images and maps; linear model of spectral mixture; analysis. Results show that the reservation boundaries are getting closer and are often trespassed by cropfields bounds. Trespassed boundaries were depicted in the northwestern edge of Enawene-Nawê along the route that links Vilhena to Juína (route MT 319). The spatial distribution of the roads in the region showed that the vicinals were the main vectors of the process that need to be continuously observed. The results allow recommending the application of the same procedures elsewhere in the country. The experience also allows anticipating that the same methodology can be used even for reservations poorly known or known just by preliminary surveys or descriptive memorials.