The contents and scope of Sustainable Development, as a model for the development towards which the international community wants to move forward, is the object of multiple interpretations. That way both, diagnosis of sustainability and the design, execution and assessment of actions aimed to the reorientation of the current model towards a sustainable model, requires a previous exercise of conceptualization and the delimitation of the concept of sustainability itself. We want to introduce in this abstract, some elements that might contribute to the necessary discussion, required for the concept of sustainable development to become operative. We will start from the events that gave origin to the discussion about the dominant development model and the first diagnosis that recognized the exhaustion of the same, focusing our attention on the evolution of the interpretation of the relationship between environment and development. We will describe that way, the process followed, till a world wide consensus was reached, regarding the definition of Sustainable Development, upon which the current international strategy for Sustainable Development is be based on. We will consider afterwards, the main elements that will contribute to the different interpretations of sustainable development; from the limitations upon which it has been built. On one side, the transformation that the adjective sustainable operates on the own concept of development (internal limit). It is therefore a question of, what are the needs to be satisfied. And on the other hand, the physical limit (external limit) related to the way the system is organized, seeking the satisfaction of the needs. Finally, we will apply these elements of analysis to the discussion of the proposal contained in the Tokyo Declaration (Brundtlan Report), upon which the international strategy towards sustainability of the Rio conference was articulated
