The puberty is an important period in woman life. We have tried to determine the age of the puberty, the chronology of its events and the real life of this period of preparation to reproductive life of tunisian girl student by an inquiry. The middle age of puberty is 13 years. It depends of sociological, economic and environmental factors. Knowledges about reproductive life are still insufficient for this age group bracket of high risks of non desired pregnancies and sexually transmittable diseases