This paper presents a cause-focused typology of 12 delinquency prevention strategies to serve as a system for organizing and conceptualizing delinquency prevention efforts. These strategies are conceptually distinct and have been designed to facilitate systematic planning and evaluation of prevention efforts and to allow for comparative assessments of the relative effects of different prevention approaches. Each strategy is based on an assumption regarding the cause of delinquency and presumes a goal of intervention aimed at modifying or eleminating the cause. The 12 strategies are: (1) biological/physiological, (2) psychological/mental health, (3) social network development, (4) criminal influence reduction, (5) power enhancement, (6) role development/role enhancement, (7) activities/recreation, (8) education/skill development, (9) clear and consistent social expectations, (10) economic resource, (11) deterrence, and (12) abandonment of legal control/social tolerance. The paper defines delinquency and prevention, discusses the need for a typology of prevention strategies, reviews prior efforts to conceptualize delinquency prevention, and describes in detail the 12 strategies. Six pages of references conclude the report. (CG)