Аннотация:The shadow economy leads to loss of integrity, deforms institutional structure of the society, undermines competition, reduces effectiveness of the economy as a whole and threatens a number of aspects of national security. According to the author, the shadow economy is not so much a neo-classic, but «institutional-evolutionary problem», i.e. it should be studied within the frames of the institutional and evolutionary paradigms. In the system-integration theory of the firm the shadow activity in each enterprise is seen as many-factored phenomenon, among the factors of which are mental, cultural, institutional, evolutionary-genetic and other factors.