The UK has recognized the need for policies to provide appropriate support and assistance to juveniles at risk of crime as the problem of juvenile crime increases and the need for multi-agency cooperation and participation to solve the problem of juvenile crime. To this end, it established a unified and consistent juvenile justice system nationwide through the establishment of the Youth Justice Board (YJB) and established close collaboration among juvenile justice-related organizations through the establishment of the Youth Offending Teams(YOTs), a multi-agency cooperation system. This has led to a significant reduction in the number of juvenile crimes in the UK over the past decade, and the number of juvenile recidivists has continued to decline, showing that the UK's multi-agency cooperation system has had a positive effect on preventing juvenile recidivism. Through the study of the UK system, it was uncovered that a multi-agency cooperation system brings expertise to the juvenile justice system by bringing together agencies involved in juvenile justice and streamlining the services provided by each agency, allowing for rapid intervention and individualized support based on the scientific diagnosis of complex juvenile crime problems. Furthermore, with certain limitations of the UK's multi-agency cooperation system, it was possible to derive implications such as the need for interventions tailored to the needs of juveniles and the importance of measuring program effectiveness. Multi-agency cooperation is anticipated that operating a juvenile protection system in line with the objectives of the Juvenile Act can be achieved by providing individualized treatment for juvenile offenders.