The work analyses the institutionalization process of Environmental Education (EE) in Brazil, stressing its tensions, consents amd fissures among the main brazilian protagonists in EE: on the one side the legal instances of Federal Government; on the other side the REBEA (Brazilian Web of Environmental Education). The theoretical frameworkis based on the critical theory, developed by Souza Santos, Castells, Latour and Maturana, about the State and the civil society relationships, their structural and organizational tensions and links in the EE field, from the viewpoint of web network. A qualitative research analyses the historical - political trajectories of EE, as well as the field works of brazilian educators. Interviews were carried among three groups: government leaders, REBEA practionners and other associates opposing the present secretariat of the institution.the research findings help to understand the EE institutionalization process, since each group reveals different spaces in its web network. The work conclusions stress the juridical and political issues of this institutionalization. Hence it pint-points partnership among the social movements represented inside REBEA, thar substituted the mostly pressuring and denouncing attitudes in 1980 decade. It stresses also that the EE institutionalization process follows the redemocratizations of Brazil, with refletions in other governamental areas. So it is observed REBEA participation in the development of public policies, both reflecting new demands of the civil society and participating in government actions and programs. It emphasizes also that State strutures were occupied by incumbents associated to REBEA, in such a way as to turn it as axis in disseminating actions and policies that reproduce tensions and links characteristic of the EE present scenario in Brazil.