In recent juvenile delinquency, as is not the case in past, the degree of misdeeds committed by boys from broken or deficit families or with personality problems is increasingly lowered, but at the same time,delinquencies are increased by boys who do not have specific deficiencies on the side of their features or of their environments but are quite normal to the effect that they are not required to be monitored. The characteristics of the recent juvenile delinquency are summarized as follows. ⑴Whereas juvenile delinquents from poor families occupied the center of juvenile delinquency previously, the delinquency has been generalized by increase in juvenile delinquents from middle class families.⑵Unlike the cases in past, the juvenile delinquency has been increased more by boys from families with living parents than by those from deficit families. ⑶The boundary between juvenile delinquents and common youths has been vague. ⑷ The younger-age tendency by increase in delinquencies by younger boys and the constant tendency toward increase in the number of female juvenile delinquents are prominent. ⑸hereas the majority of juvenile delinquents consisted of boys with or without jobs in past, most of the juvenile delinquencies are committed by school boys recently. ⑹Boys with strong non-social properties have been more increased than boys with anti-social characteristics.Changes in juvenile delinquency include increase in misdeeds as extensions of everyday activities, lack of the sense of guilt, opacity of the distinction between misdeeds and everyday activities, increase in non-social misdeeds, increase in misdeeds by students, younger-age tendency among juvenile delinquents, rarefaction of delinquency etc.Since recent juvenile delinquents and forms of their misdeeds are revealing quality changes different from previous ones, effective measures for recent juvenile delinquency seem to be difficult to devise with the analysis based on the previous concept of misdeeds and juvenile delinquents.Thus, this paper aims to survey the concept of misdeeds and juvenile delinquents and divide the trends of juvenile delinquency in Korean stepwise to clarify the characteristics of juvenile delinquency in each step and the changed concept of misdeeds.