The aim of the thesis is to try to answer the question of knowing how specificities of the steps of life of the young of popular suburbs. if any, are taken in account in the public policies, and particularly in youth policies at local level, especially by the local councils. From which references and which representations of youth are these policies elaborated ? And, at last, whatmakes that sometimes the young accept this policy or resist the « formalisation » of youth policies.For that purpose, after having suggested a sociology of contemporary youth, and emphasized on the specificities of the steps of life in popular districts and precised all the limits and the aims of youth policies, the thesis attempts to analyse the way the young are taken in account through different strategic paths, leading to action, particularly citizenship and participation, social and professional insertion, and access to public space.This thesis, written after convention of professional research with the Brittany Region and the Pays de Loire Region, was elaborated after matters provided from a research in different cities : Angers, Brest, Lorient, Nantes, Quimper, Rennes and Saint-Nazaire (67 interviews involving youth professionals and city councillors, 55 with young from popular suburbs and asession of many days of reflexion with these same actors)