It is known, that in case of world economic destabilization prognostic mistakes can not only lead to deterioration of a government but also promote strengthening of crisis tendencies in regions. It makes experts to improving algorithms of social and economic forecasting and gradually to replacing 'static' and 'quasi-static' models of a society by 'dynamic', which includes nonlinear feedback through elements of an economic infrastructure. Quite often this feedback becomes "critical", that is it starts process of transition of territory's economic complex to a new condition with unpredictable in advance properties. In these cases we often speak about occurrence of "critical infrastructures", those are capable to affect essentially on social, economic, environmental, etc. safety of territory. In advance, it is not always known, that infrastructures can appear critical, therefore the risk-analysis should include a stage of their detection on the basis of preliminary formed system of criteria. Designing of criteria of criticality and carrying out risk-analysis becomes complex methodological problem in conditions of continuous change of the importance of parameters of regional social and economic system. Their decision demands participation of the big number of experts which should understand each other and for this purpose to apply the uniform approach to definition of concept of "critical infrastructures". Until now different authors define in their own way terms they use. There is a situation then the significant number of infrastructures drops out of consideration as "critical" because they did not render essential influence on social and economic position of region. The role of the specified infrastructures can suddenly increases in conditions of world crisis. The specified circumstance has caused necessity of revealing of such "latent" potential infrastructures and has become the reason of performance of the presented research. In the work we started with discussed before assumption, according to which occurrence of critical infrastructures influences essentially on stability and as a consequence on safety of regional social and economic system (hereinafter -. regional SES.) [1]. Thus, for revealing conditions of "criticality" of an economic infrastructure it is necessary to make the list and to estimate a level of regional risks. The analysis of publications of various authors has shown that usually basic risks and concept of safety of the regional SES are connected with conditions of existence and ability to react to external influences. Thus existence of regional system during life cycle is postulated as preservation of its qualitative definiteness even at change of structure of system and functions of its elements [2] (figure 1). Thus as one of a condition of occurrence of a "critical" infrastructure it is necessary to consider occurrence of preconditions for change of qualitative definiteness of the regional SES.