Industrial Ecology (IE) has emerged as a pathway to make critical changes from the linear economic model. Self-organizing business strategy among firms, its development has required a public participation. Public action intervenes in the projects by measures of coercion (regulations, environmental laws) and incentives (financing, tax measures, technical and organizational support, etc.). They play an important role for mobilizing stakeholders by creating social, organizational favorable context. Even if governmental intervention influences the emergence of concept, several others factors are useful for sustainable projects. This paper aims to underlines key these factors of the success of industrial ecology’s projects. From analysis of two projects implemented in Kamouraska (Quebec) and La Rochelle (France), we draw the influence of policy instruments, spatial proximity, ecological values, social proximity and mechanisms of project’s management or coordination.