This article starts with the premise that a classical approach of the law such as the one taught by Hans Kelsen leads to an impasse when it is time to conceive a model of recognition of the Native's "Custom Adoption." The author proposes to take an approach of the law with a view both anthropological and pluralistic in order to study the question. In Canada, the legislatures of one province and two territories have already sanctioned the formal recognition of "custom adoption." These examples will serve as the background to the discussion of the different forms of expression of legal pluralism. The author will argue in favour of a model of recognition that expresses a pluralism of co-operation or co-ordination since it is the model that offers the aboriginal system of adoption the best guarantees of independence and autonomy.