Basis of the economical integration were set through the Treaty from Rome, closed in 1957. The realization of the economical and monetary union asked by the economical integration, are the most important success of the European project. For the realization of the economical integration were necessary an entire series of political economy measures, of the transformations of the economical, socials and institutional structures which exist at the moment. The economies generated by the production on large series: is the result of a bigger efficiency, based on an optimal dimension of the enterprise, which permits medium costs smaller and, through this, the possibility of increasing the competition on the international market. The scale economies are possible in some economical branches only when the production is realized in units with large dimensions and of large series, sustained, in the sane time, by a great technological advantage. On the other hand, only the biggest enterprises, which generate the scale economies, could be marked out on the national and international markets. One of the anti-arguments, which can be said, is the fact that by the scale economies obtained in the integration areas benefits, at least in the initial phases, the large transnational enterprises. For the European Union, these enterprises are north-Americans or Japanese, which take advantage of the large dimensions of the integrated market. To eliminate this inconveniences it must exists a monetary union, with the same juridical cadre and a united values market, with a total mobility of the funds. The funds will be directed towards those financial centers in which the settlements are favorable to the investors, the costs of the risks management are reduced at minimum, the costs with assuring and reassuring polices are, as well, very reduced for the investors, so they can enjoy the financial comfort and prosperity.