The objective of the research which is part of a doctoral thesis, was to establish changes in environmental education (EE) teaching models within the framework of a participatory, formative, self-critical and reflective process of basic education teachers in Ibagué, Colombia. For this communication in particular, results of the model built by the biology teacher of the seventh grade of secondary education are presented. Methodologically, the research is qualitative, with features of action research and the case study for a deep understanding of what is studied; a previous online questionnaire was applied in order to know the initial ideas of the teacher. Once his initial model was identified, he participated in spaces for training and critical reflection in discussion groups among peers; In parallel, he developed his plans, classes and recordings to reflect on his teaching model. As a result of the work during a school year, the teacher achieved changes in her thinking and performance, planned and shared among peers, trained, evaluated, improved and rebuilt her teaching model. In conclusion, to improve the teaching of EE, teachers require training processes that allow reflection on their practice and be accompanied by investigative processes to be agents of change. Keywords: changes, teaching model, environmental education.