Abstract: Dismantling of colonial system, break-up of the Soviet Union and Yugoslavia, a series of protracted unresolved political ethno-confessional conflicts in multi-religious regions brought another topicality to the questions of essence and functions of the state with undetermined political status. The absence of criteria of national identity, recognition and solvency brought to widening of variety of problematic political and territorial entities. Regardless of differences in internal structure and position in world political system, I suppose, they may be considered as a whole entity called “disputable states”. In this study I have tried to analyze available concepts for defining of various forms of problematic quasi-public entities and rectification of “disputable states” concept. The main methodological approach of the research is new institutional economics.