Diploma thesis deals with the connection between the nature of implemented peacekeeping operation and possible positive output of this activity and thus with successful peacebuilding in the specific context of etnopolitical conflicts. Etnopolitical disputes constitute a vivid challenge aimed towards United Nations organisation. Mainly, because this organisation is one of the main actors of international system in finding solutions of etnopolitical conflicts and because United Nations also proposes concrete tools for their resolving - peacekeeping missions. We work with assumption that the nature of etnopolitical conflict and the nature of conflicting parties involved influence, to an important extent, involvement and impact of peacekeeping operations in resolving these conflicts. Diploma thesis, through the use of theories of origin and solvability of ethnic conflicts, creates the framework within which their more complicated solvability can be explained as well as inhibitors of theoretically successful models. Likewise, the typology of peacekeeping operations is defined and also narrower understanding of peacebuilding, as a set of political and security aspects, is described. Datas from four case studies then offer an opportunity to formulate partial endings and findings of examined causal relation. C lick...