In stating a legal issue in the domestic law of a country, when an element outside the borders of that country is found in the background of the issue at hand; The matter that has arisen from the internal dimension reaches the transnational dimension and takes on an international aspect. This item causes a branch of the science of law called private international law to be established. When a foreign element is present, conflicts between the internal laws of countries become more apparent than before and what becomes the criterion for action is the determination of the law governing this type of claim. The discussion of respecting the boundaries and rule of law of countries is an issue that should not be neglected because in line with international decency and policy, in order to avoid conflict, it has been considered obligatory to honor and respect the internal laws of other countries, to the extent established; However, in the case of adoption or guardianship, where the rights and interests of the child must be adequately and adequately secured, before entering into the substantive challenge, the competent authority and law for the hearing must first be determined in terms of form. During the investigation into the issue of protecting orphaned or maltreated children, we find that this worthy act of the revealing religion of Islam has been mentioned and the legislator has taken steps in detail in the legislation of internal order and regulations, in accordance with Islamic standards. Ultimately, the resulting attention has caused the aforementioned legal institution to be distinguished from other states in the international arena due to inheritance. In the matter at hand, whether we call it guardianship according to the rules of the country of Iran or adoption according to the regulations of the country of France; the issue of inheritance, in terms of its main description and importance, will necessarily be decided with regard to the law of the seat of the examining authority.