Currently, the Syrian crisis has become one of the pivotal issues for decision-making in Iran's regional foreign policy. In this research, we’re going to answer this question the functions of the foreign policy of the Islamic Republic of Iran in the Syrian crisis, what is based on the elements of national interest of this country, and also the hypothesis studied the foreign policy of the Islamic Republic of Iran in the Syrian crisis, based on the fight against terrorism and maintain the security of civilians, maintaining the existing political situation and support the legitimate government of Syria and finally, maintain stability and security in the Middle East according to Islamic standards. This paper is intended addition to addressing the important parameters of Iran's foreign policy toward The Syrian crisis, exploring the reason for adopting these policies from the perspective of the theory of Islam and with a focus on an Islamic State (Islamic Republic of Iran). Iran to maintain, spiritual and worldly interests, geopolitical conditions and influenced by the structure of the international system, has adopted specific strategies such as having a strong national government, geopolitical situation, and ideological element that gives in this country a prominent role in regional issues. Therefore, the Islamic Republic of Iran is an important role in the Middle East with innate rationality in deciding the direction of strengthening the position and increasing its moral and material interests.