Introduction : Adolescence is a wonderful period in human life. It is a bridge between child hood & adulthood WHO definition : 1.Progression fi-om appearance of secondary sexual characteristics to sexual & reproducing maturity. 2.Development of adult mental process & adult identity. 3.Transition from total socioeconomic dependence tolerate independence AIMS & Objectives : 1.To study the age & menstrual pattern at menarchy 2.