This thesis discusses aspects relating to the discursive change that is occurring in the field of science education, in which the purpose of citizenship assumes a central position. With the purpose of identifying and situating the tensions inherent to these changes and the different perspectives on citizenship, we discuss the relations established in the governmental regulation actions of school science textbooks production. Our analysis were based on the Critical Discourse Analysis framework, an methodological approach that considers texts as components of social practices and searches on comprehend how discourses figures in these practices and orientate social changes. In this perspective, texts are pointed out as a social and historical construction and in a dialectical relation with discourses and social practices. Critical discourse Analysis methodological framework works with de concept of interdiscursivity and the categories of discourses, genres and styles, elaborated in the dialogue with the contributions of the language studies developed by Mikhail Bakhtin, Michel Foucault, Michael Halliday and Basil Bernstein and with the notions of ideology and hegemony. Based on this framework, our analysis of the discourses on science education and citizenship were performed in a set of texts of the Programa Nacional do Livro Didático (PNLD), the public policy of evaluation and purchase of school textbooks and in a set extracted from the textbooks, with the goal of apprehending the meanings of citizenship in this textual chain. Our analysis points to a recontextualization of the debates on science and citizenship performed in the field of science education research in PNLD’s texts. In these movements, the debates are recontextualized in the form of a set of prescriptions and assertions, adopting a communicative strategy typical of the educational reforms, based on ruptures and replacements, which wipes off the tensions inherent to changes. Differently, the analysis of the textbooks points that these tensions are deeply marked on the text, which stresses the character of hegemonic struggle between the established practices and the attempts to change.