The aim of this article is to define model describing dynamics of bankruptcy and foundation of new enterprises. In the first part we try to answer what is bankruptcy in law, economic and social sense. It results from overview of the literature that bankruptcy is as natural as growth, and both of these contradictions are complementary. An important inference is also a need for improving bankruptcy mechanism, because the more efficient it is, the healthier market surrounds us. On the basis of bankruptcy there emerge new firms. We derived procedure in order to forecast the number of new firms. The conclusion is that dynamic mathematical models may be useful tool of prediction of number of new firms founded.