There are many changes that could occur with teenager. When they are growing up such as physical, mental and emotional change. Adolescents behavior may be affected by these change. These behavior might be caused by first of all, a parent foster is considered as the most important factor that influence on their children’s later behavior. Secondly, friends can be another significant reason for those changes. Teenagers are more likely to think that their friends will face similar situations. Finally, social environment played such an important to teenager behavior. Teenagers will absorb all of the things they have seen and heard from people around them.