As part of its mission to assist the Ecology ministry in setting up the National ecological network, Cemagref carried out a comparative analysis on network formulation methods to assist in the establishment of national guidelines. This article presents the salient points. The French ecological network aims to preserve and restore ecological continuities. In support of the Ecology ministry and the National ecological-network implementation committee, Cemagref coordinated the drafting of national guidelines. As part of this work, Cemagref identified significant national and regional projects and compared the methods used. Elements for a national framework and recommendations for the design and mapping of the network on the regional level were presented to the committee and, following review, were included in the national guidelines.