Spatial Data Infrastructure (SDI) appears nowadays as an essential driver of institutional data diffusion. Due to the dual impact of systems interoperability and changes in the legal framework, institutional spatial data tends to become more and more accessible through widespread deployment of SDI at every scales. In this context, the French research program “GEOBS : Spatial Data Infrastructure in the informational governance of environment" (2015-2017) lead by the French National Centre for Scientific Research (CNRS) aim to make spatial data infrastructure not just a research tool but a real object of research for a better understanding of the flow of environmental information. To do this, we develop a prototype observatory by indicators of contents and uses of the 65 french SDIs. These indicators propose some (spatial, temporal, thematic, organizational) markers to analyse spatial data patrimonies nowadays accessible and to analyse territorial and informational recomposition they translate. Our analysis of SDI as a sociotechnical system allows us to identify some issues related to the question of the production and management of knowledge on the environment. This contribution aim to present the GEOBS project and his methodological solutions to analyze how the contents of Spatial Data Infrastructures are currently evolving. The future developments of these methods are expected to allow more accurate and data-based interpretations of the political role of these new and original public institutions specialized in information management.< Réduire