The biodiversity issue is being politically constructed by international agreements. These agreements reflect two mains foci: the economics of genetic resources, the rights to access and benefit from biodiversity. As for other global environmental issues, biodiversity requires a form of collective action adapted to contexts of scientific uncertainty and lack of clearly identified stake-holders. Where standard economic theory is constrained by its fundamental hypothesis, convention theory opens a new perspective to these questions for economists. The paper demonstrates that the convention theoretical framework could be usefully applied to the understanding of the social construction of global environmental problems, and the identification of possible solutions. Convention theory may be used in order to underline legitimity conflicts among actors with contradictory goals, means rationality and perceptions. This paper emphasizes the building of shared common perceptions on which the international agreements on biodiversity were based on. The shared common perceptions are related to the diagnosis, to the objectives and policies for a collective management of biodiversity. We discuss the role of economics for the production of scientific knowledge and the status of economic norms in this decision making process.