This paper aims to assess the degradation of vegetation in the transition zone between the sedimentary and crystalline in central Benin. The method used is the geomatics and includes the photo - interpretation assisted image classification, the calculation of vegetation indices and spatial analysis. The results show that despite its high coverage (75.21%), unevenly distributed among the dense forest (40, 50%), open forest (15.03%), woodland (16.47%) and tree and shrub savannah (28.00%), large bare surfaces indicate a risk of desertification and loss of vegetation. Image processing from vegetation indices showed that the degraded vegetation is characterized by low coverage containing low biomass and having a healthy and low density. The highest rate of degradation of vegetation varies. The sharp deterioration represents 8.89% of the dense forest, 76.83% of the woodland, 72.89% of woodland and 100% of the tree and shrub savannah. Degradation of vegetation is related to the importance of human pressure in the south and center of the study area, the sedimentary basin, and insufficient water in the North, on the crystalline basement.