Following the failure of the Iranian people in the Constitutional Movement to restrict the king`s power through the parliament, a system-making revolution emerged and became a platform for the three powers of the new system to be established. Despite the activity of numerous political movements in Iran after the victory of the revolution, the status of the legislative pillar in forming the new system became very important. This article seeks to elucidate the role of the Islamists in creating and strengthening the legislative pillar of the system derived from the Islamic Revolution. The Islamic current, using traditional organizing power and modern view of political participation, based on the ideas of Imam Khomeini, compiling the regulation of election, presenting a single list in Tehran, introducing outstanding figures in other provinces, accepting fundamental offices in the first parliament, presenting the drafts and surveying the bills , opposing opponents in the parliment and helping other pillars, has performed its most important tasks in the formation of the first parliament. In this research, library data has been analyzed in a descriptive-analytical method.