The economic union of some countries of the certainty? With certainty the majority of the politicians and the economists will say that yes. To extend the economic markets, creating great blocks, as the European Union, the Mercosul and of other regions, without a doubt is very important, in view of the creation of an area of I still deal free of tarifrias restrictions eliminating customs burocracias and over all creating an area of performance with a profusion of economic agents. The lesser doubt does not exist of that this fortifies all the involved ones in the common market, attracts investments and handspike the development. But from there to create an only currency of legal course in the economic community, beyond reckless, an enormous migraine for the involved ones can become, has seen the events that are occurring in the zone of euro. As a former-president of the Brazilian Central Bank said, ‘ ‘ the union is incomplete. It is monetary tidewaiter, but not fiscal, nor poltica.’ ‘ She is extremante difficult to create a complete integration, and without the complete integration, of very little will advance to make a monetary integration. Before the total impossibility of if promoting an integration politics and inspector, the ideal is to make a economic integration, that minimizes the customs barriers aiming at the expansion of the economy of the countries members, however without the creation of an only currency of legal course. Viable it can be the creation of a virtual exchange currency for the block that is resultant of the weighed average value of the value of the currency of each country member, quoted to the exchange of a general purpose world-wide currency, that has still taken in account some factors such as growth of the GIP, the fiscal situation, the human development, the inflationary level, the degree of indebtedness, the level of economic reserves, the stability politics and the democratic level of each country member..