The article intends by examining the cultural and social policies of Reza Shah in Iran an Ata Turk in Turkey, in favour of strengthening secularism and nationalism, attempts to categorize the relating stepts taken in both two countries. To consider the characteristics of both leaders, their views toward religion, status of clergies, judicial, system, education and etc., this investigation seeks, by applying comparative method, to indicate the similarities and differences of steps taken in the social and cultural context of new Turkey after the collapse of the caliphate and modern Iran after the constitutional Revolution.