In Iran, the altar is considered one of the most important parts of a religious building and it shows the skill of the artists who built it. In the history of architectural decorations of Islamic art, altars have always contained the best and most valuable examples, both in terms of construction methods and in terms of motifs and values ​​of calligraphy and calligraphy. Among the methods and techniques used in decorating altars, using gold tiles is one of the most difficult and at the same time the most beautiful methods. The masterpieces left from the altars of Zarinfam show the peak of the use of decorative techniques for the construction of altars.The Zarinfam altar of Imamzadeh Ali bin Jafar Qom is one of the most magnificent Zarinfam altars, and among the Zarinfam altars belonging to the Ilkhani era and existing in Iran, it is considered the largest among them, and due to the fact that it was not visible to the public for many years, little information is available about it. Maybe it is because so far this unique masterpiece of Iranian art has not been properly introduced and its visual and content quality has not been studied and reread. The purpose of this research is the thematic and visual analysis of the golden altar of Imamzadeh Ali bin Jafar Qom as one of the masterpieces of altar making and the largest golden altar of the Ilkhanid era in Iran.The results of the research provide important information about the status of the Zarinfam tile and glaze industry in the Ilkhanid era, the name of the manufacturer, the year of production, and the visual and thematic quality of the largest Zarinfam altar of the historical Ilkhanid period in Iran.