The Institut de formation des bibliothécaires, created when the statutory changes of the library professions occurred, tries to think about the initial and continuing training of these professions. The intention to precise the aim and the content of these trainings leads to wonder about the competencies existing in the libraries and about the relations between training and professional identity. What university references can be called on for the initial training to be constructed ? Is it possible to define the library science as an applied science ? To imagine an initial training separated from the continuing one ? Or are the library professions not being built through a continuing education which is still to think up ?