The competences to cooperate/collaborate are amongst the first to be developed in many educational frameworks. Within digitized societies, they promise efficiency, innovation, and well-being at work. However, these competences are not put forward in profesionnal organisations, and they are lacking from adult training courses.Based on this observation, this thesis aims at identifying the competences to be developed to work more easily with others. Bringing light on the abilities to act, convienently called “collaborative competences”, and on the way which they can be developed through training are the objects of this study.Thoroughly analysing the context of a hybrid training is carried out based on the study of the profesionnal trainingcourse “Animacoop: animating a collaborative project” which concerned 200 interns from 2010 to 2014. In this study, collaborative competences are analysed in link with profesionnal experiences and collaborative projects.Falling within an empirical approach, the research methodology connects a few data collecting tools (questionaires, interviews, observations) and on a conceptual level mobilises the Activity Theory and the notion of Training System .This research offers a model of key competences to lead a collaborative project. It analyzes the training system as a strong internally coherent ecosystem, open to development, prone to creativity, which favors collaborate competences development.