The scope of this research is determined in matters of inheritance and the determination of the law applicable to disputes concerning legal relations tainted by a foreign element in inheritance. We examine the rules of attribution related to this issue in Iraqi law, Moroccan law, Algerian law and the law of the Arab Republic of Egypt and the ideas contained in these rules and controls of attribution, and limit the scope of our study to the position of laws on conflict of laws in inheritance with different nationality. We have taken the method of  comparative research  as a platform in our research by clarifying the concept of inheritance in language, terminology and law and we clarified the definition of inheritance with different nationality and then we clarified the legal nature of inheritance with different nationality as well as the statement of issues involved in the idea of inheritance and its content and the nature of inheritance in Iraq, Morocco, Algeria and Arab Egypt and we discussed in determining the law applicable to inheritance with different nationality deduced the rule of reliance applicable to inheritance issues. And we dealt with the subject of the  research divided into three sections with the introduction and  conclusion and as follows : the first is  the subject of the introduction and we touched on the subject of  inheritance and its provisions in the law,  while we dealt  in the second  section the rule of attribution related to matters of inheritance and will, either the third section has been specialized in The role of the national judge in the application or exclusion of foreign law relating to inheritance and probate matters.