This article deals with the question of the role of the structures of governance of SMEs' competitive clusters in the development of capacities of cooperation. The study conducted on a SMEs' competitive cluster in the PACA Region highlights that, when firms don't have access to the same cognitive or relational resources, the role of governance is not to reduce at all costs the difference between the participating companies, but to ensure the balance integration / differentiation in order to allow knowledge accumulation and diffusion.