According to Ancient Egyptian myths, in Heliopolitan theology, it was in Heliopolis that the god Atum created the world, and the ancient group of the nine gods known as the Ennead were worshipped there. Heliopolis was the main cult center of the sun god Ra who took the leader role in the Ennead of Heliopolis as early as the 5^th dynasty. In Heliopolis the cult of stone symbols and sacred animals was known as the bnbn, iwn pillar, the bnw, Mnevis bull and mongoose. Another important symbol of Heliopolis was a sacred Persea tree called iSd. The iSd tree supplemented the cult of stone symbols and sacred animals and became a very important sacred symbol that exceeded the borders of Heliopolis to become a central subject which contained the keys to divine order. The tree appeared in coronation scenes and scenes related to the Hb- festival, in the Book of the dead, besides its importance as a fruit, leaves and flowers. This paper aims at investigating the importance of the iSd tree and its appearance in scenes and texts. This paper begins with an introduction of the importance of the city of Heliopolis and the origin of the iSd tree, then focuses on the practical use of the tree, as well as its religious and spiritual importance. The study ends with a main conclusion.