With the Mongol invasion, most of Iran’ s civilization heritage, such as schools, mosques and cities, was destroyed. However, after the presence of Hulagu Khan in Maragheh and with the establishment of the World Science Center at the Maragheh Observatory by Khajeh Nasir al-Din al-Tusi, the production of various sciences, architecture, and urban planning progressed greatly. During this period, in order to decorate the INSCRIPTIONS, they used plasterwork and tiling with Kufic, Naskh, Thuluth and Bannaei Scripts. The ARCHITECTURAL INSCRIPTIONS of this period are decorated with Qur’ anic verses, the Prophet’ s narrations, guardianship, executorship and Salawat on the twelve Imams. For example, in the tomb of Ö ljaitü in Soltaniyeh, in the interior decoration of one of the porches and the outside part of gateway of east door, the words "La ilaha illa Allah", "Muhammad Rasoolullah", "Ali Wali Allah; Ali Wasi Rasul Allah" have been decorated. This paper seeks to explain the place of guardianship and guardianship of Amir Mo’ menin in the INSCRIPTIONS of this period through a descriptive and analytical method and direct observation of the historical monuments of Ilkhanate Period. The hypothesis of the paper is that these INSCRIPTIONS are valuable historical documents about the religious image of Iranian society and show the tendency of the inhabitants of center of Iran to the guardianship of Ali and Ahlul Bayt.