The concept of specialization of intra-urban space is first defined as the fragmentation of the urban fabric into numerous unifunctional zones or sectors. The study then examines the main transformations which have occurred in Charlesbourg since 1954 and seeks to identify indices of specialization. The study is composed of three parts : analysis of pattern, analysis of evolution and analysis of factors underlying the spatial transformations. Part I provides data on Charlesbourg which permit the reader to easily follow the discussion. There, an elaboration of the various physical (morphology), administrative (cadastre) and developmental (built up space) characteristics serves to describe the pre-specialization Charlesbourg. Part II analysis the changes produced between 1954 and 1974. For each time period studied, the existence and organization of zones and sectors are illustrated. An attempt is made to characterize the tendency toward spatial specialization. Part II explores the factors underlying these tendencies. Taking into account parts I and II, part III develops a set of laws or principles, primarily economic but also spatial, which explain the specialization of urban space.