Architecture of Safavid era in Isfahan has attracted the attention of many researchers and has motivated discovery of temperamental evidences. People like Steiren and Corbin have tried to interpretively decipher its codes. However, it seems that understanding the Safavid Era’s position in history is a necessity for understanding the architecture of that time.The atmosphere of the society was Shia-Iranian and all the philosophers believed in independent rational forms and “Plato-like ideas”. Wisdom of Islamic-Shia art in “Safavid era” was realized because of the tendencies to illumination, dreams, philosophy of singleness of mind and world of spirits and angles.The limbo world is between the “delivery” and the “temporal” world, possesses a special conscience place in “Shia’s Ideology. “Corbin” in his investigation of “Shia” states that the world of idea in “Shia “has is the origin of formation of a science called “mraya science” and it is the manifestation of a symbol which Corbin calls “the mirror”.Indeed, a “Shia” artist refers to the image of the heaven as the ultimate desire of a human beings and resorts to limbo as an interface between the Earthly world and the afterlife and by using the knowledge of heaven gained through the “Quranic” verses and “Hadayeth”, he reflects this image in his designs. Afterwards, he uses decoding geometry and images, which expresses his discovery and intuition in the world of ideas. So, the “world of idea” which based on the spiritual and “Platonic Idea”, has passed to the Safavid Era and manifested itself in the society.Thus, this paper seeks to prove the hypothesis that Safavid architects attempted to portray the “idea’s universe” in their masterpieces. To this end, they, first, attempted to express this ideology in depth, from Plato’s view to Molla Sadra’s and Shia’s beliefs.Then, it explores and expresses the scope of their effects on the structures of the Safavid Era by studying the decorations of the Imam Mosque of Isfahan.The first philosopher, in Iran, who has seriously elaborated on the Idea world, was Suhrawardi. His point of view, In addition to Khosravani wisdom, was influenced by the Greek philosophers, particularly Plato’s. After Suhrawardi, the Islamic philosophers in the Safavid Erasuch as Molla Sadra have expressed their opinion on this issue in more detail.Henry Corbin Believes that Shia’s teachings call for prophetic reception of Platonic wisdom. Prophet’s mission is to create convergence between earth and sky. But this convergence is figurative and is based on the Idea world. These opinions consistent with those of Sadra and Suhrawardi.In general, the principals of Idea World in Molla Sadra’s view, includes the following: Limbo is between the intellect and physical worlds. It draws form from the intellectual essence and gets matter from the physical essence. It is the intuition world. This world exists in the physical world both in the descending arc and the climbing arc. This paper explores how these beliefs are manifested in the architecture a decorations.Essentially, the religious art, especially in the Islamic mosques discussed in this article have one factor in common, their symbolic aspect. In all of them, the world is a shadow of the truth. Designs used in the decoration of mosques, is no exception. This motif is logical thinking of the Iranian artists. Through simple shapes, they have used a set of icons and symbols to express specific concepts.The mosque’s decoration is represented in four ways: Motifs flora, fauna (rare), lines, and geometric designs DECORATING Techniques which were been used are Stucco, brickwork and tiling. Tiling is seen more than the other techniques. Therefore, this paper mainly concentrates on the tile-work’s designs. Part of the tile-work is Arabesque (Eslimi).The tiles’ decoration is, sometimes, in line form. Right from its inception, this sacred art was a tool for religious expression, Hadith, different names of God and, most importantly, verses of Quran. Another important issue in tiling is that secret codes are embedded in the colors used. Turquoise and azureblueare the symbolic colors of the sky. In sayings of the Prophet Mohammad (PBUH) emeraldcoloris associated with the afterlife. Moreover, as it is believed by the Muslims, God created heaven white and white is the most popular of all colors before God.Finally, the Imam Mosque of Isfahan’s decoration indicates the following: a) Herbal designs a figurative motif of life tree given is seen in the holy Quran as a harbinger. The frequency of these motifs reveals the embodiment of the artist Msalyn that the Shia believes that the holy Quranis portrayed in the Bible. The frequency of these motifs reveals the artist purpose to embody the idea world in the Shia’s belief and the holy Quran.b) Numbers and colors used in, according to the verses and narrations, are attributed to the Heaven.c) Making earthly paradise was the common wisdom of the era’s dominant the oretical belief, because philosophy, creed and religion were united in this period.Finally, the Idea world in Shia’s belief is embodied in his doing. That is in climbing and descending in creation. So, it makes the terrestrial paradise through reference to the verses and had it has the sources. The idea world is an interface between this world and the heaven, the afterlife.