Times have changed and social issues have changed too. The problems arising among young people are in an alarming state. The main problem like gangsterism is affecting the development of the country. It is an ever-growing problem in the world, especially among teenagers. For example, a young rabbinical student was stabbed to death during the 1991 Crown Heights, NY, riots when the jury acquitted his attacker of state murder charges (Satris, 2002). The most important early risk factors for violence between the ages of 15 and 18 are involvement in general crime and substance use before age 12 (Office of the Surgeon General et al, 2001). The situation becomes more serious when the number of male and female primary school students increases. Pupil participation in gangsterism is increasing. What is gangsterism? According to Collins English Dictionary in 2009, gangsterism is the culture of membership in organized criminal gangs. Hence, the purpose of this study is to investigate the factors of gangsterism among adolescents. There are several reasons why teenagers get involved in gangsterism, such as peer pressure, family problems and financial problems. First, some studies have shown that peer pressure puts a child at risk for later involvement in gangsterism (Fitch, 2009). ). As teenagers, they are very sensitive during this period. They are also easily influenced by their friends. A study on gangsterism in Malaysian secondary schools showed that friends exert a greater influence on students than family (Yahaya, Boon & Buang, 2008). Adolescents with weak social ties are those who attend few social activities and have low popularity among conventional peers (Office of the Surgeon General & et al, 2001). They are aggressive and antisocial. This type of teenagers is more… middle of paper… gangsterism is influenced by peer pressure, family and financial problems. As time passes, the rate of gangsterism increases. A survey of 20,000 high school students by the Centers for Disease Control in Atlanta revealed that one in five youth reported bringing a gun to class (Bryjak&Soroka, 1994). If we don't prevent it well, maybe in one day it will become a war. The whole world will become full of violence. People can live in fear. They will not feel safe and calm. The relationship between them will become worse. Teenagers are pillars of the nation. If we don't curb it, the entire life of teenagers will be destroyed by their hands. The nation's economy will decline rapidly. People will live in poverty. Hence, gangsterism must be prevented and avoided. As residents, we need to take some actions to prevent this problem.