This document shows the work of pedagogical practicum I and II developed within the research group Conocimiento Profesional del Profesor de Biologia, in the Universidad Pedagógica Nacional (UPN) with students of sixth semester of Biology teaching degreeer, with the purpose of contributing to the construction of the Professional Knowledge of Biology Teacher through the field work as a strategy in Biology teaching.In a first approach the students conceptions about the relationship between the field practicums and the professional knowledge of the Biology teacher were investigated,finding out that the importance of field praticums is considered only from their role as students and their effect on the construction of biological knowledge without taking into account their importance for their teaching task.In that sense, it is important like a learning content to favor the pedagogical practicum as a strategy in Biology teaching in the sixth semester students, by means of workshops, reflections and a space in which the future teachers designed a field practicum for students of the second grade of secondary in a public educative institution.Such spaces and reflections allowed the future teaches to consider the pedagogical practicum as a strategy in Biology teaching, which contributes to the construction of own knowledge about the Biology teacher.