1. Introduction There are various theories about what is holy and is unholy, and their causative agents. Generally, due to these theories, it can be said that communication with supernatural forces, differentiation, perfectionism, and being free from any contamination, are the most important holy attributes leading to a sense of fear and attraction in believers. These attributes in the Islamic culture go back to the nature of God, and accordingly, the creatures are sanctified to the extent that they possess this divinity. Based on these definitions, one of the holy manifestations can be the tree. The nature of the tree as a masterpiece of creation has always been admired and respected by various peoples, as much as it has been praised as a totem. Accordingly, this article attempts to examine the concept of holy issue, methods and holiness factors of the tree in the popular culture of the people in the field of civilization of Halil Rood. 2. Methodology According to the field of study of this paper - which is popular culture – the method of collecting data is the field method. In this way, the authors have gathered information on this subject by attending among people and visiting holy places and phenomena. The research method is also descriptive and analytical method. It means that firstly by describing the holy phenomena, the characteristics of the holy trees are shown. Then we analyze the reason and condition of the holy issue according to a semiotic approach. "Semiotics is the study of everything that points to something else. Semiotics is associated with the production of meaning and representation- as the Meta-analysis- seeking to show how meaning is constructed through the interaction of signs with one another. Meaning is influenced by systems and codes, so it is necessary to reach the methods of meaning, to obtain the codes or systems that govern the phenomena or texts. Accordingly, the goal of semiotics is to classify and regularize the structure of texts in order to achieve systems that consciously or unconsciously create meaning in the texts. Myth, too, has a very high capacity for semiotic analysis because it wants to provide a symbolic response to ontological and metaphysical ambiguities. Myths consist of signs that symbolically represent the ideal human world. Although different myths differ in details, but derived from human mind, it can admit that they are similar in structure and pattern. The holy issue- as already mentioned - is the basis of religion and mythology, which has manifested itself in various forms and traditions in the mental structure of man and mythology. Accordingly, the semiotics of myth is an attempt to achieve the unifying structure of the human mind and the integration of its mental products. From a semiotic point of view, any phenomenon that enters into the mythical structure, based on the contradictory structure of the human mind, enters into one of the holy antithetical categories, and accordingly constitutes a part of the myth as a whole. The holy and the unholy are also understood in this way through the contrast. 3. Discussion Sanctification (holiness) is a kind of cultural process that connects man with the meaningless nature in a supernatural sense. So every sacred thing is as a material symbol that is accompanied by an immaterial (spiritualistic) sign. This transforms sanctification into a process of sign that is achieved through the co-existence and succession of signs. The Sanctification of the tree also has a symbolic mechanism. It means that the tree, through its succession and communion with the sacred phenomenon, transcends its material status and becomes an immaterial (spiritualistic) phenomenon. Old age and greenness are the factors that can distinguish one tree from the other, and this distinction gives the tree a new and unmistakable image and brings it into the sacred structure. This distinction results in the "perfection" of the tree. One of the trees with this feature is the cypress tree. Being old and green as a distinctive and natural characteristic of the cypress and its association with saints such as Prophet Zoroaster is one of the main factors of sanctification of the cypress in Iranian culture. Trees and other plants, not through themselves, but for the sake of what they discover, become manifestations of power and take on a sacred aspect as a religious matter. One of these discoveries is the medicinal and medical properties of some trees. Linked to the phenomenon of human life, death, and immortality, this gives the tree a symbolic aspect. Symbolism of the tree with the sacred and the cosmic issue has appeared in the myths in the form of the body of God in the form of a tree, depicting the plant gods. The medicinal property of the tree is the characteristic that separates and transfers the tree from the natural status to the sacred or holy status. Any phenomenon can be sanctified by being replaced by the divine, such as the old age and the medicinal properties mentioned before because it indirectly replaces the immortality of God. Sometimes the sanctification (holiness) of the phenomenon is made not by the substitution property, but by the proximity and co-existence of the sign with the sacred or holy issue. Lotus, for example, is sanctified because of its proximity to burial places or Imamzadeh or Ghadamgah for "something else" on it. In other words, by its presence in the proximity of the sacred or holy place and by the natural property of its tree (resurrection) it repeats and renews something superhuman (female fertility) and becomes a symbol and allegory as a matter of divinity. In the structure of religions, this sanctification (holiness) usually manifests itself in the form of specific individuals (prophets, imams, devotees, etc.). Any phenomenon that somehow falls into the companionship of these people can have the attributes of the sacred or holy issue. The attribution of the palm tree to Ali (AS) is one of the reasons for the holiness of this tree. In the field of Halil Rood, any tree that is in any way related to the world of the dead and the world of jinn, and in general to the mysterious forces, is taboo and sacred. This means that it simultaneously evokes a sense of admiration and fear. The source of this fear is the belief in the supernatural and evil force that exists in the tree. 4. Conclusion The main reason of the holiness or sanctification of the tee comes from the natural and intrinsic properties of the tree itself, such as the constant growth, renewal, and greenness of the tree that has led to an animistic and vibrant thinking about it and has found a supernatural power. In some cases, the communion and succession of the holy tree has made it sacred. From a semiotic point of view, it can be said that the meaning of the holiness of the tree is formed by differentiation and difference. That is, the distinction that creates a supernatural belief about the tree and turns it into a sacred concept. The results of this study show that this distinction and holiness in the tree is mostly made through the process of companionship and in some cases by substitution with the sacred issue. Until the tree enters into the sacred structure of myth through the human mind, it is a sign as other signs without any particular meaning, but becomes a holy and meaningful element upon entering the sacred structure. This structural character is not just limited to the tree and can encompass other broader contexts such as place, time, objects, rituals, and so on. In the cultural domain of Halil Rood, this sacred inclusive structure is present.