This paper presents the legal developments contained in the Mercosur and the Andean Community of Nations CAN towards the creation of a South American Common Market SCM; the Mercosur law and Andean law, and the jurisdiction to the guarantee of the establishment of the Common Market. In this paper SCM means the two independent integration processes in South America i.e., Mercosur and CAN. Although within these organizations there are significant advances in the regulation for the construction of a common market, they are not sufficient to be able to speak of the existence of a Common Market. The article deals with the perspectives for an SCM with the adoption of the Treaty of Unasur. Finally, one takes the European Common Market as a comparative model for South American integration. In this sense, the analysis addresses the Common Market, the Common Fundamental Freedoms and the relationship between the Common Market and European Union law.