This paper is to study some problems of the Korean Juvenile Act and tries to make some Proposals for it`s improvement and modification. Nowadays there are some suggestions regarding age levels which the Act sets concerning juvenile delinquents according to the developmental stages of children. While the suggestions are mostly to seek more effective ways of coping with the juvenile offenders based on the educational and rehabilitative ideas, some proposals show that the ideas is now on the way of transformation from the classical aspiration of making children more educated and more adaptable to the society to a strategy of ``getting tough`` to the juvenile delinquents. And it is commonly noted that the Act has some weakness in achieving its goals, and the available measures it deploys have some problems for attaining its goals. Concerning the suggestion of reducing the age of criminal incapacity, that the suggestion basis of some empirical studies formerly performed by the Korean Institute of Criminology(KIC) research staffs and some criminological and developmental child psychology, that the suggestion has little persuasiveness. Another suggestion that require the reduction in the age at which educational measures may be applied to the juvenile who commit offenses that the educational capacity(from 12 to 13 year old offenders) is considered. This paper proposes that the educational measures available to this group be made more efficacious before the reduction in the age level. With regard to the third suggestion that juvenile age level should be reduced from 20 to 18, which is based on the one hand criminological and on the other hand socio-cultural reasons, we can find that the former reason is little persuasive, because the suggested target(enlarging the punishable age extent) may be achieved by the established age level system. But we can take the latter reason seriously because the maturity may depend and may be conceived largely on the social consensus of the society.