The countries of Iran and Russia have been two important hubs on the two sides of the Caspian Sea, located in the regions of Hartland and the Rimland. The geopolitical and geostrategic importance of these countries to other countries in the region has led to a dynamic role in the political equations of Central Asia and the Caucasus. Since today power and geopolitical weight in international relations has become more and more important, Russia is regarded as a global power and Iran as a regional power, the two countries have always apply this factor of power in their policies. The realism theory of Hans Morgenthau, which emphasizes the balance of power and the role of power factor, is a proof of this claim. Geopolitics is the study of the interaction of geography, power and politics, and the actions they bring together. The most common boundary between geopolitical knowledge and international relations can be found in the theory of realism. Morgentha, as one of the theorists of international relations, believed that international politics was governed by universal and objective laws based on national and national interests, and not on the psychological drivers of decision-makers. Based on this theory, statesmen think and act within the framework of their own interests defined as power. The research methodology is descriptive-analytic. First, the required information was collected using library method and by referring to authoritative sources, books and articles. Then, a geopolitical analysis of the relations between Russia and Iran after the Islamic Revolution was discussed on the basis of Morgenth's theory. This research tries to answer the research question; is the doctrine of Russia's powers of power and hegemony changed before the collapse and seeking global peace and security? Or is it seeking national interests and the expansion of vital space through close relations with Iran in regional and global affairs? During the post-revolution period, relations between Iran and Russia in general and in the past decades, in particular, have not reached a strategic level because of the wrong believes of the Russian scholars and government towards Iran and, conversely, the wrong believes civil society and people of Iran towards Russia. Relations between the two countries have developed in the post-Islamic revolution in various fields. Iran and Russia pursue national goals and unique geopolitical codes in their foreign policy, and regulate all their regional and global movements based on this geopolitical compass. Russia is trying to maintain and extend its national interests with Iranian support in the region of Southwest Asia and Central Asia and the Caucasus. On the other hand, Iran has, more than ever, been cooperating with the Russians over the past decade due to establishing a common point with Russia in pursuit of its ideological and national security strategies. From the point of view of analyzes based on the realist approach in international relations, the close proximity of political relations between the two countries can be interpreted in the need for a balance of power or a common threat from the United States. On the other hand, the Islamic Republic of Iran is trying to maintain its regional strength against Saudi Arabia and Turkey in the southwest of Asia. The convergence of common goals in regional issues between Iran and Russia has made the two countries more closely aligned with each other. Although Russia has had a double cooperation with Iran to fight ISIS and to prevent the influence of this Takfiri terrorist group on its borders and geostrategic territories (which are considered as geopolitical interests), its main goal to expand its hegemony globally and rival NATO and leave it out of the geostrategic bottleneck in the world make Russia to work together with Iran in various ways. From the analysis of various aspects of Iran-Russia foreign relations can conclude that the Russian federative republic is a tactical ally and can be regarded as an ugly attitude in the field of foreign relations. Russia pursues its own interests, regardless of Iran's interests.