Besides the fact that the Current International Public Law considers the right to citizenship as a fundamental human right, where the citizenship is also the object of international regulations when a person stays abroad or in areas that are not subject to the jurisdiction of that countries, or when there occur transfers of populations or territories from one state to another. The International Public Law is also concerned with situations where a person, either has two or more citizenships (dual citizenship or multi-citizenship), or is deprived of his or her nationality (statelessness) or finds himself/herself in particular circumstances, such as aliens, refugees, migrants and others. The main purpose of the investigation included in this paper work is to identify and set up the citizenship conflicts due to differences in the regulation of the acquisition and loss of citizenship between the laws in the matter of different states. The conflicts of citizenship could result in international misunderstandings and disputes. In order to remove such situations or to prevent them, the states proceed to the conclusion of international treaties, and namely to the creation of relevant international laws. Primarily, they insist that International Law does not restrict the freedom of states to determine by the internal law the legal status of their own citizens, but may determine the conditions under which the established legal status is opposed to other states.