(en) This action research focuses on the teaching of writing in French as a foreign language in university in Vietnam. Its objective was to develop an educational device to improve the teaching/learning of French as a foreign language in general and especially in writing. After the delimitation of contextual and theoretical frameworks, a diagnosis of the problem situation was made by a statement of errors made by students in their written productions and analysis of questionnaires sent to teachers and students. The assumption was then made that a device taking into account the difficulties of learners, the three areas of writing and teaching approaches enrolling in the action-based approach can overcome the difficulties of students and promote the acquisition of competence of written production. A writing project was developed, implemented and validated through a process of quasi-experiment.