The purpose of this thesis is to investigate how Euclides Roxos´s role in the reform of secondary mathematics teaching in Brazil, during the 1920´s and 1930´s contributed to the establishment of mathematics education in Brazil. This study has two parts. Initially, in order to understand how an engineer could propose innovations in the teaching of mathematics it was necessary to study his life, since he entered the Colégio Pedro II as a student through his first years as a teacher in this institution and at the Escola Normal. After this, we analyze how the curricular changes proposed by Euyclides Roxo, at first just for the Colégio Pedro II and based on the international reform movements, altered significantly the teaching of this subject, as for example, the curricula, textbooks, and teacher education. Thus, we were able to establish some characteristics of this period, starting with Euclides Roxo viewed as an individual in a mesh of interdependent relations. The documentary basis for this research was composed of material from the Arquivo Pessoal Euclides Roxo, Centro de Memória do Instituto Superior de Educação do Rio de Janeiro, mathematics text-books used in Brazil, and of past researches on the subject of the thesis, which belong to the area of the History of mathematics education in Brazil, with the intention to offer some relevant contributions to this area.