This research presents works on the construction of the experience of teacher trainees by the practice of drama according to an "analysis of the activity" approach. The goal was to treat the following question: at which conditions can a theatrical practice help students to enter their "role" of future teachers, and thus to help them to act later in class? A praxeological stake to help the designers of training programs with professional-qualification aim guided the production of scientific knowledge. Three categories of empirical materials were used to build the data: a) observation data collected during the training session; b) self-confrontation data gathered from interviews led just after training sessions; c) data of interviews led some time after the training sessions. The data analysis was driven in reference to the semiological approach of the "cours d'action" (Theureau, on 2004, 2006) that allowed to describe and to interpret activities of the participants. The scientific contribution of this research allows to propose a new orientation in the field of teacher training: to focus on the creative activity of the trainees encouraging the emergence of "potentialities to act" in unforeseen situations, encouraging the self regulation, the analysis of collective practice, the opening on the environment. So, even if it seems paradoxical, a game of improvisation in a situation remote from the professional context and in reassuring conditions can turn out to be a "space of encouraged actions" (Durand, on 2008) for the future teacher.
