This study examined the formation of three ritual altars and changes in hanging Buddhist paintings with a focus on the Joseon-era practice of setting up three ritual altars in the main halls of Buddhist temples. The arrangement of main halls in Joseon-dynasty temples, which were filled with Buddhist paintings, has been disparaged as symbolizing the laxity of Buddhist faith or as simple-minded pursuit of meritorious retribution. However, considering that temples with a different name for the hall maintain a similar composition regarding Buddhist paintings, it is evident that a common perception existed in regard to the essential composition of paintings that were to be enshrined within the main halls. This paper highlights the relevance of Buddhist paintings displayed in the main halls of Buddhist temples with reference to main literature sources including compilations of Buddhist rituals published between the 15 th and 19th centuries and ritual eulogies in literary works of monks. The diverse range of Buddhist cultures across East Asia shared ritual procedures due to the dissemination of ritual compilation books, but the development of temple facilities and mediums took a different path in Joseon from those of China and Japan. Instead of building an exclusive space for rituals as was the custom in China with “the water- and-land ritual halls ( 水陸殿),” Buddhist temples in Joseon generally used the main hall of Buddhist temples for rituals and thereby prepared the three ritual altars to perform rituals within the hall. The basic structure of Buddhist rituals, which were completed through offerings and banquets for each of the three ritual altars, can be identified in records dating back to the early Joseon dynasty, and the rituals for the three platforms have influenced the arrangement and composition of Buddhist paintings. As the three ritual altars were prepared as a permanent installation within the hall, the paintings hung inside were each referred to as “upper-altar painting,” “middle-altar painting,” and “lower-altar painting,” instead of being named based on the themes depicted. Arranging the paintings according to the three-platform structure was one of the consistent principles that defined the composition of Buddhist paintings within the main hall. Meanwhile, changes began to appear to the themes of Buddhist paintings referred to as middle-altar paintings depending on the period.