The article includes: (1) a brief history of the Act; (2) four sets of assumptions regarding man, society and the purpose of the juvenile justice policy; (3) analysis of the values assumed in the eight principles of the Act and comparison of the values with the four sets of assumptions; (4) discussion of several implications that may emerge from the particular combination of assumptions in the Act. The four assumptions mentioned above are classified into four models--Crime Control, Justice, Welfare, Community Change-- and details are provided for each model. Provisions of the Act and analysis of its principles are included. It is likely that, instead of a delicate balancing of principles, implementation of the Young Offenders Act will be guided by standard operating procedures within juvenile justice bureaucracies, the primacy of mandatory as opposed to optional provisions, and the financing available in each region and province allocated for experimentation with new and creative programs. Tables, endnotes, references