[en] This document first presents the context of the French project of national strategy for biomass mobilisation (SNMB) as an application of the law related to energy transition for a green growth, and also as an item within the complex set of strategic documents such as the national strategy for low carbon, the national programme for forest and wood, the multi-year programming of energy, regional climate-air-energy schemes. It presents the SNMB project, its scope (with some recommendations made by the Environmental Authority), the usage challenges, the present situation of biomass with respect to the SNMB objectives for different biomass sources (forest, agriculture, breeding, by-products and wastes). It briefly discusses procedures related to the SNMB and to its environmental assessment. The second section addresses the analysis of the environmental assessment. It formulates some methodological recommendations, discusses the articulation with other programmes, and the initial analysis of the environment and of its perspectives of evolution, comments the justification of choices made regarding substitution solutions. It comments the analysis of likely effects of the SNMB implementation, and measures to avoid, mitigate or compensate these impacts. It briefly discusses the assessment of Natura 2000 effects, and choices made by the SNMB regarding indicators and modalities of environmental follow-up