Abstract : In 1971, the French Socialist Party had been refunded, in order to rise to the power. In 2007, the PS lost the presidential elections, which are now its “natural” aim: it is now a government party, better electoraly implanted has ever. This electoral success supposed deep transformations of the PS. Indeed, the structure of the party was based on the mass party model; its members want to see it as a « parti de militants ». However, whatever the party is or would be, its leaders must adapt the party organization conforming it to its new government party statute. That adaptation is shortly tied to the links existing now between the French socialists and the State. They adjust for that reasons the party, facing the power's constraints and what is more difficult, the growing professionalization of its elites. But, contrary to what the growth of the public funds in its budget, the redeveloping of its party in the central office or even the increasing weight of elected people in the party suggest, the PS deep rooting into the State, its cartelization, is not a necessary phenomenon. First of all, the PS organization is the objectification of the socialist's party configuration. A party configuration is the result of the party member's interdependency that tied them together. The rising to the office and the electoral success deeply transform that configuration: it directly hurts the form and the representations of the socialist organization. So cartelizing the organization then becomes a forever unending mean to integrate inside party's form the configuration's evolutions. Finally, the PS aim to get to the power is not contested any more today. This will not have been possible without its organizational cartelization, which was the price for the socialist's party configuration well functioning. That configuration was slowly and sometimes with difficulty adapted according to the party's statute. Even if the representations of the “parti de militants” still persist, at the end of the changing process, the French Socialist Party is definitively now a real party enterprise.