The objective of our work is to provide some aid to the maintenance of a web site. The webmaster would like to get a semantic follow-up of the users’ browsing, but he only has at disposal a set of statistical tools that indicate the frequency of one page visits but on no account by semantic aggregation of concepts. In this article, after having presented the methodology to modelise a web page while taking into account the semantic aspects, we will define the semantic analysis part of the web site and we will finish by a description of the global ontology in XML with instance storage. From local ontologies defined by users' categories, we are extracting semantic information. These results allow to do a revision of the site analysis or of the site design.