Nowruz is one of the ancient rituals that is celebrated every year with the beginning of the spring equinox in Iran and the countries affected by the Iranian civilization as well as Turkey. Nowruz is a cultural phenomenon and can be a key element for connecting the countries that organize it. As two neighboring countries, Iran and Turkey have always had social, economic and cultural relationships with each other. One of the most important common cultural elements between Iran and Turkey is the ancient Nowruz. The question of the present article is what are the similarities and differences between Nowruz in the two countries of Iran and Turkey and how is the role of Nowruz in the cultural diplomacy of the two countries evaluated and what are the common cultural lines between Iran and Turkey. It seems that according to the importance of soft power and cultural manifestations, Nowruz can help to deepen cultural relations between Iran and Turkey. The ceremony of welcoming Nowruz, house shaking, Haft Sin table, buying new clothes and seeing and visiting relatives are among the common features of Nowruz between the two countries. From the point of view of differences, Nowruz in different parts of Iran and Turkey has differences regarding how to hold the ceremony and the anthropological differences that have been mentioned. The research method is using library resources and collecting data from articles, books and examining them in a descriptive-analytical way.