The aim of the present analysis is the design of a reliable automatic updating process for the IGN BDCarto. Geographic evo— lution is a dynamic phenomenon, whereas cartographic updating, more static, requires the knowledge of a geographic state at one moment. In the GIS context, digital data gets a dynamic dimension, and the updated database must be in coherence with the initial one. Thus, two aspects have to be focused on : detect the changes and keep the inter-temporal coherence. Tests, composing an automatic updating in a test-area with an existing process, showed not reliable enough results. The main problems we met with such a process is the variability of interpretation, which drowns the real changes supposed to be detected. The difficulty is reinforced by the generalization operations imposed by the data-base specifications. To minimize errors induced by those aspects, an improved updating process may be envisaged, in which knowledge of a priori evolutions would be introduced. The proposed solution consists then in including constraints, probabilistic for the evolutions and geometric for the generalization, in a fuzzy classification.