This study examined the environmental factors that increase juvenile delinquencies, reviewed the current state and problems of the policy for protecting delinquent juveniles, and proposed improvement plans. Environmental factors that increase juvenile delinquencies are believed to be rapid urbanization, the malfunction of families and schools, changes and diversification of the value system, the influence of mass communications, etc. Therefore, as social and political measures for protecting delinquent juveniles, it is necessary to promote juvenile delinquency prevention movements by local societies, reinforce the function of families, strengthen the all-round education of schools, establish a new value system, and tighten regulations on mass communications harmful to juveniles. In addition to these, as measures based on the Juvenile Law, it is required to individualize and diversify educative measures, pay special attention to sending delinquent juveniles to training schools or reform schools, develop various types of training schools and their programs, create regulations on the juvenile diversion of the police, and assure a due procedure in the protective process of juveniles.