Ever since Raoul Blanchard has written his « regional studies » about Québec, the concepts of region, regionalisation and regionalism became common use. During more than 25 years, they have been closely associated with planning, development questions and with the fight against regional disparities. In this paper, we examine the different uses that have been made of these concepts and the evolution of the regionalisation Systems; this come after the analysis of Blanchard has made of regionalisation and regionomy particularily in his work entitled Canada français.