The work describes a program of action-research carried out with secondary education science teachers. The program persues the professional development through the curricular innovation, taking as promotional agent the action-oriented reflection, lending itself special attention to the socialization of the teachers. Throughout two school years actions directed to such effects were taken, organizing themselves through pedagogical content knowledge. The results show that the teachers, in a slow and gradual form, are incorporating new practical theories to their reflections and work in the classroom.