It has been widely accepted that the Second Vatican Council could be seen as a milestone in the history of the relationship between the Roman Catholic Church and other great world religious. Meanwhile, there are still different (if not contradicted) interpretations toward the exact doctrine of the Council of non-Christian religions. This article tries to offer a "traditional criticism" of the official documents related to this subject in order to find what the theology of religions of Vatican II really is. In doing so, I view the Catholic theological tradition of "nature and grace" as the most crucial hermeneutical context, and consider that it could also justify the Council’s teachings about non-Christian religions.