Youth crime is a common and serious problem in today's society, and people, particularly parents and educators, are very concerned about the developments in this problem. According to Bala and Roberts, approximately 17% of criminals were youth, compared to 8% of the Canadian population aged 12 to 18 between 2003 and 2004 (2006, p37). As a large federal country, Canada has taken a series of measures since 1908. Until now, there are three laws in the history of the Canadian juvenile justice system: the Juvenile Delinquents Act of 1908, the Juvenile Justice Act on Young Offenders 1982 and the Youth Criminal Law 2003. Justice Act. In Canada, the justice system and the principle of these laws have been the subject of debate for a long time. This article will explain how these three laws were defined and why one was replaced by another. Before 1908, the nature of the developing society pushed at-risk children to commit crimes. In the 19th century and even the beginning of the 20th century, society had many orphaned and neglected children. They came from Europe or other colonies and could lose their parents on a long journey. The defense doli incapax, "incapability to do evil" – children under seven (in some cases the maximum was 13) were incapable of committing a crime, was initially presumed. This misled that young people could be innocent when accused in all cases. However, children might have the same intelligence as adults in knowing the consequences of bad things. Thus, children convicted of a crime would be subject to the same penalties and would be treated as adult offenders (The Evolution of, 2009, p1). However, sometimes the punishments went beyond justice: these children were severely punished for minor criminal acts. others, intensive support and supervision orders, deferred custody and supervision orders, and non-residential program participation orders. Since their introduction, the new penalties have not been commonly used. In 2006-2007, deferred custody and supervision orders were made most frequently in only about 3% of guilty cases in youth court, or 1,080” (May 2008). In conclusion, the development of the juvenile justice system results from social development. and human needs. By modifying and integrating, judicial authorities have made the legal system more efficient and fairer for young people, provided that necessary sanctions are carried out for criminal acts while protections are given to ordinary young people. the stability of a society depends on a strong judicial system.