Abstract : This thesis takes into account the effects of the experience and expertise on the practice of teaching in physical education. This research in “Savate Boxe Française” questions the meaning that the physical education teacher gives to his professional practice which was analysed from the crossing of theoretical data of the clinical didactics. This scientific direction based on the theory of the subject in teaching, "divided" between often conflicting constraints, allows the researcher to identify the personal relation of the practitioner with the activity that is taught, that is the subject of the contingency of the knowledge transmission. It specifies and justifies the use of a methodological point of view of the three times of the clinical didactics analysis: analysis of “déjà-là” that provides information on the intention of the teacher, the observation in situ “l’épreuve” of teaching and the interviews of “après coup” that enable the teacher to reflect about his own activity and the researcher to infer the causes of the didactic phenomena observed. Inter and intra sites analysis compares them in order to identify the specific effects of the experience and expertise.Our final project is to present a "generic framework" analysis and interpretation of the teaching practice articulating the didactic and clinical dimensions to test our hypotheses.