A second entrance door for analysis of stability contracts, is that gave us the study of contracts of States, since here we find the typology and the characteristics of formation of a contract in which intervenes the status as a Contracting Party and which is projected towards individuals for promoting their participation in the economic process. In this part of the investigation we were able to have evidence of the error incurred many scholars of law, to have been confronted with the idea of the civil contract, giving him permanent and absolute category. in this line, the work center in the characterization of the State contract and an analysis of the elements of the process of formation of the same, making a permanent contrast with the idea of the civil law contract. Way to go complementing the study we are of the idea that legal certainty, within the development of the relations between public interest and the private interest, will be important inserted into the recruitment process publishes, since the increased interest of the contracting issue, is the value which means the referral process is planned in order, giving him consistency, so that its rules do not shrink between if and are applied in the cases for which have laid down, without being repealed singularly. After the analysis of the general theory of State contracts, figure of the contracts of stability, in our view, must no longer be labeled as an administrative contract or a civil law contract, and that its design has been taking elements belonging to both fields. Stability agreement will accept mutual consent as a matrix idea of private law, but infers a legal consequences by full margin of private mechanics. in terms of its nature legal, we must say that, in the end, do not want say that it is a civil or administrative, contract but rather put emphasis on one creates legal relations between the parties and is binding the parties and is obligatory for them. .