The agency theory through the model «shareholder is useful to describe the contractual relations between all the speakers and to explain the government of the agricultural cooperatives. However, the agricultural cooperative is a "contracting nexus" which is the place of crossing of several fascinating parts, whose interests can diverge.The need for setting up a system of government company is due to the divergences of interests between the various parts of stakeholders. In this paper we explain this divergences in the case of cooperative firms.