Ethnics in Iran, both before and after the formation of the nation state, have always been the focus of intellectuals, elites and ruling political systems. Before the establishment of the nation state in Iran, the ethnics were mostly considered by intellectuals, mainly in order to reconstruct Iranian nationalism, and often in books, newspapers and poems. In the first and second Pahlavi's periods, it was mainly archaic nationalism that gave existence and meaning to the ethnics and considered them as a threat to the extended identity system. But after the victory of the Islamic Revolution, we are faced to a kind of transformation in the discourse regarding ethnic groups. This different discourse, in the early years after the victory of the Islamic Revolution, clearly shows itself in the sphere of Imam Khomeini's discourse. This article, Basing on Imam Khomeini's discourse, examines the principles of ethnic policy in the Islamic Republic of Iran. The structural approach was used as a theoretical framework for realizing this goal. The speeches of the Imam in the Sahifa of Imam were used as data. The master signifier of the discourse governing ethnic politics in Imam Khomeini's thought has been unity. Issues such as equality, brotherhood, denial of division, conflict and denial of ethnocentrism can also be mentioned as floating signifiers.