Achaemenid official art often appeared in wall and rock relief, and its main building was laid during the time of Darius I. The Rock reliefs of Behistun and the tomb of Darius are two main Achaemenid monuments painted alternately during the reign of Darius I, and many motifs and features of Achaemenid art appeared in them for the first time. Therefore, the study and comparison of these two illustrated monuments will lead to a better understanding of Achaemenid official art and its formation process. This research aims to study and compare the motifs and pictorial features of the Behistun relief and the Darius’ tomb relief to identify similarities and differences between these works in order to know the extent and how Darius’ tomb relief is influenced by the Behistun relief and to gain more knowledge of the developments that took place in the early stages of the formation of Achaemenid official art. The research questions are: How and to what extent the Behistun relief has influenced the tomb of Darius the great relief, and to recognize which motifs of Achaemenid art appeared for the first time in the Tomb of Darius the great relief. The current research was carried out with a descriptive-analytical method and a comparative approach and Its information is collected in a library manner. The results of the research show that through the representation of all the main elements of the Behistun relief in Darius’ Tomb relief, this relief has been largely influenced by the Behistun relief. Also, some motifs and pictorial characteristics of Achaemenid art first appeared in the relief of Darius' tomb and then reflected and expanded in other Achaemenid works.