Definition of evolutionary processes for critical infrastructures are given in the work. Analytical model of evolution are developed, on the basis of semi-Markov theory. Formula for calculation of basic system characteristic of evolution (mathematical expectation of time needed for evolution) are purposed. Some minuses of analytical approach for solving of the problem of critical infrastructures evolution researching are listed. Simulation modeling is purposed as an alternative solving for the problem. Keywords: evolution of Critical Infrastructures, concept of "potentional", semi-Markov Model, simulation modeling.
