Introduction and Objective: The main objective of this research is to examine the evolution of the sun and moon symbols in ancient Iranian art, especially in the Sassanid period. Throughout history, symbols have been considered as a tool for expressing and visualizing concepts and ideas, representing various cultural and social beliefs and values. The sun and the moon, as two important natural phenomena, have always had a special place in human life and beliefs; the sun is known as a symbol of life, light, and power, and the moon is known as a symbol of fertility and growth. Focusing on the Sassanid period, this research seeks to provide a more comprehensive understanding of the symbolic meanings of these two elements in ancient Iranian art and civilization. Examining the evolution of these symbols through the study of related Sassanid artistic and historical works that display the symbols of the sun and the moon is one of the main objectives of the research
Method: This research was conducted using a descriptive-analytical method and used artistic content analysis and symbology. In this regard, library resources and historical documents were used as the main sources of the study. The collected data included coins, crowns, bas-reliefs, metalwork, and plaster field works from the Sasanian period, which clearly used the symbols of the sun and the moon. The analysis of these works using written sources and religious literature of ancient Iran has contributed to a deeper understanding and analysis of the content of the symbols. The use of previous research in the field of symbology and the history of ancient Iranian art, especially in the Sasanian period, has also been among the methods used in this research 
Findings: In Sasanian art, the sun was depicted as a circle with radiating rays, an eight-petalled flower, and a spoked wheel. These symbols were widely used in coins, crowns, and other works of art as symbols of power and monarchy.  Animals such as the lion, eagle, mountain goat, and horse are also known as symbols associated with the sun, each of whichh played a specific role. The moon, as a symbol of fertility and renewal of life and in connection with natural changes, had a special place in ancient art. In the Sasanian period, the crescent moon next to the sun was a symbol of balance and harmony between two opposing forces (light and darkness). The ram and the cow are also seen as vital symbols associated with the moon in many works of art, which indicates the value of the moon among ancient Iranians. In Sasanian works of art, the combination of the symbols of the sun and the moon with other animal symbols such as the lion, eagle, and ram shows the balance that exists between the different forces of nature and society. These combinations are also clearly seen in Sasanian crowns, which expressed the greatness and glory of the Sasanian emperors. The symbols of the sun and the moon in Sasanian art not only expressed decorative concepts, but also delved into religious, political, and social issues.  The sun as a symbol of Ahura Mazda and the moon as a symbol of Anahita, the goddess of fertility, are embedded in the religious and ritual beliefs of this era and are clearly depicted in artistic and cultural works 
Conclusion: The present study shows that the symbols of the sun and the moon played a key role in presenting religious beliefs, strengthening national identity, and highlighting royal power in the Sassanid period and in ancient Iranian art in general. These symbols were manifested as a link between religious, cultural, and political components in Sassanid art and had an important role in the social and political life of this era. The balance and harmony created by combining the symbols of the sun and the moon with other artistic elements helps us to better understand the complexity of history and the depth of culture of this era. Understanding these symbols helps us to achieve a more accurate and deeper understanding of ancient Iranian history and art and to recognize their important place In the history of Iranian art and culture.  These symbols continued to manifest the forces of nature and reflect the deep religious and cultural beliefs of the society, some of which have survived to this day.