Abstract : Since about fifty years, the dynamics of orientation is in the center of the social, political and educational concerns. Numerous researchers conceptualized determiners at work in the elaboration of the choices of orientation: Bourdieu and Passeron ( 1964 ) adopts a sociological point of view with their model of social reproduction, when the others develop the psychological angle of the process of orientation, in particular the notion of project (Dubet, 1973 ; Boutinet, 1990,1992, 1993 ; Dumora, 1990 ; Guichard, 2006).We wish to contribute to the effort of construction of knowledge by developing an explanatory model of the choices of orientation at the time of the entrance to the higher education and the pursuits of studies, little developed still in France: the influence of the relationship to knowledge on the choices of the students. We build in particular our theoretical model on the basis of the researches for the team Escol (Charlot, Bautier, Rochex) on the relationship to knowledge of the pupils and & al. ( 2005 ), who works in Belgium on the relationship in the knowledge of the students.To confine this vast domain of search, we make the hypothesis that the choice of orientation in the entrance to IUT (university institute of technology) G.E.A. or to university section AES depends on the interaction of socio-bibliographic variables (such as the quality of the previous programme, the sex, or the social origin), and of subjective variables, with in particular a specific relationship to knowledge. In other words, the interaction between these two classes of variables captures the unique relationship with knowledge involved in orientation process and continuing education. By adopting a longitudinal angle over 3 years after the registration in the higher education we hope to bring to light specificities of relationship to knowledge explanatory of the choices of orientation and pursuits of studies.In time 1 our sample is composed of 265 students, with 147 students enrolled in first year of IUT GEA, and 118 students enrolled in first year at university AES. Order to respect the objectives of the comparative longitudinal study, we have only maintained the students of the times 2 and 3 "locatable" in time 1. Also, in time 2, we have 81 students (58 students enrolled in second year of IUT GEA, and 23 students enrolled in L2 AES section at the University) and three times we have 25 students (19 graduate students DUT -two-years technical degree - GEA previous year, and 6 students in L3 AES section at the University).To collect the data, we conceived a questionnaire in two main parts: the one concerning the reasons of the choices of orientation and the other one the relationship to knowledge of the students (Rey & al., 2005). Our results reveal that the choices of orientation and pursuits of studies are effectively influenced by the socio-bibliographic characteristics (in particular the social origin and the quality of the previous course) and psychological characteristics of the students.Besides, the choices of orientation and pursuits of studies are also determined by specific types of relationship to knowledge.