In this research, firstly, we summarized the life story of Hz. Ali, who is one of the four caliphs of Islamic world and focused on the reasons of loyalty and affection of the Islamic world to Hz. Ali. The main subject of the article is the inscription of "Ali" in the Turkish Architecture in Anatolia in the Middle Age as one of the ways of expressing this affection and loyalty. Attention has been drawn to the inscription of "Ali" noticed among the geometric decorations as well as the inscriptions handled both openly and decoratively.