A system of psychological knowledge on criminal subculture is formulated, its basic elements are desribed in terms of pedagogical, developmental and juristic psychology, its specificity is shown. A paradigm of this field of scientific knowledge is outlined. Concepts of criminal subculture and its criteria, stratification and criminal hierarchy, values and criminal traditions, «thiefs law», «order», «execution», «tiny exceptions», nicknames, criminal jargon, swears, damnations, stygmatization, ostracizm and some others are considered as basic ones. The knowledge of modes of communication and information exchange in criminal subculture gives an opportunity to anticipate its development, to comprehend its essence, and the dynamics of its value, "laws", and traditions among youngster, and to put forth uncustomary methods of preventive actions.