After the victory of the Islamic Revolution and the formation of revolutionary institutions in the field of domestic politics and national governance, the establishment of an institution to supervise and manage regulations to ensure their compliance with Islamic laws in order to preserve the achievements of the Islamic system was on the agenda of the revolutionary political elite. The function of the newly established institutions was clear and they were created to strengthen the Islamic system in terms of content and function. The Guardian Council is one of the institutions of the revolution that has various functions to strengthen the Islamic system. The legal and jurisprudential nature of this institution has led to its special supervisory function being prominently raised. In the present study, the authors seek to examine the function of the Guardian Council in the political system of the Islamic Republic of Iran based on the functional structural theory. Hence, the following question is raised: What function does the Guardian Council have in the structure of the Islamic Republic of Iran? In response to the above question, the following hypothesis is raised that the Guardian Council has a vital function in the field of legal-jurisprudential supervision in the structure of the Islamic Republic of Iran. The research method in the present article is descriptive-explanatory and the method of collecting documentary sources.