The widespread role of parties in international relations and its influence on the foreign policies of governments has formed a new type of diplomacy, which can be interpreted as party diplomacy. On the one hand, parties play a role in the public arena and on the other hand by participating in foreign political institutions. Therefore, it can be said that if parties play a role in international relations, party diplomacy is in the middle of official and public diplomacy and is different from them; Although it overlaps with both areas in parts. In this article, by using the descriptive-analytical method and examining the indicators and effective policies in party diplomacy, we are looking for an answer to the question, what is the position of party diplomacy in Iran's foreign policy? In this regard, the hypothesis raised is that nowadays party diplomacy is one of the important tools in the relations between countries and due to its inherent structure, it is different from official and public diplomacy procedures. The published reports indicate that in the last two decades, only the Mutalfa Islamic Party had foreign relations. For this reason, this article evaluates the position of party diplomacy in Iran, focusing on the foreign relations of Mutalfa Islamic Party. This article looks at this issue not from the perspective of international relations, but from the perspective of foreign policy as an important branch of public policy. The method and tools of this article include the descriptive-analytical method using historical studies, the scope and level of party cooperation, the position of party diplomacy in legal approvals, as well as membership in unions and regional and international cooperation of parties.