In this book, two issues "citizenship" and "the status of foreigners" are discussed and compared from the perspective of contemporary law and Islamic law, and attempts are made to show the advantages and privileges of the Islamic legal system in comparison to the contemporary law. The first section of the book includes topics such as citizenship origin and history, definition and description of citizenship, types of citizenship, and more importantly, the proof of citizenship in the Islamic legal system, types of getting citizenship (primary citizenship and acquired citizenship), and techniques to end citizenship (change of citizenship and deprivation of citizenship). The second section also includes topics such as definition of foreigner, history of foreigners’ status and the foundations of foreigners’ rights, privileges and duties, as well as restrictions, deprivations, and exemptions of foreigners in the field of public law (including administrative and political rights, freedom of religious behavior, liberty and personal safety) and private law (namely personal status, family rights, contracts, transactions, etc.).