This survey is based on the assessment by remote detection of the deforestation in the forest region of Masako in Kisangani (RDC), it aims to quantify the dynamics of the soil occupation while using the techniques of the cartography by remote detection as well as those of the systems of geographical information. We had used of the Landsat pictures TM p176r060 of January 1990 and March 2001, to make the cartography of the soil occupation, the method of the post-classifications has been used, six classes have been kept in order to apply a SIG under Arcgis 10, The matrix of confusion has been used to validate the results of the classification, the matrix of transition and the yearly rate of deforestation, have been used to quantify the fragmentation of the forest landscape. Of the gotten results, the methods prove that him ya had a change in the occupation of soil of it spaces it of 11 years. So while comparing the gotten results, we noted that the forest landscape is in full change in Kisangani. Fragmentation remains intense for the classes of the dense forests and the secondary drill. The dominant class is the one of the fields and fallows.