Politics is formed within a discourse based on the dual concepts of hostility and sympathy or antagonistic and agonist relationship with “other” discourses. Through the definition of politics, discourses determine the identity frontiers between the “insiders” and “outsiders”, on the one hand, and define the political conflicts on the other hand. This plays a remarkable role in clarifying the current status of political parties, discourses and dialogues and finally political development and political culture. Based on these preliminary facts, this research tries to study the concept of politics in a determining and important course of contemporary history of Iran i.e. Islamic revolution. Applying discourse theory by Laclau and Mouffet, this research seeks to find what formulations of the concept of politics have been proposed by political discourses in post-revolutionary Iran. To find an answer to this inquiry, two discourses of Islamic liberalism and political Islam, which have found an opportunity to create a system or, in other words, a political discourse within the political system, have been investigated.