Using titles and epithets on the coins of the ancient era, along with other imprints, was considered an essential tool for conveying the king's message to the territory under his rule. The order of using these titles and epithets, their meaning, their change and development in different types of coins of a king also includes subtle points that are worthy of being noticed and evaluated in connection with the historical events of that time. Parthian kings used epithets and titles that express their social, political and historical position. The magnificent examples of these coins in terms of design and writing were minted during the reign of the Parthian Mehrdad II. With his accession to the throne in 123 BC, the rise of the power of the Parthian dynasty began and was followed by the expansion of their governmental territory. Examining the coins of the Parthian Mehrdad II shows that with the passage of time and his aging and as a result of historical events, his titles and epithets underwent transformation. These changes can be traced on the basis of the types of coins attributed to him and with a specific order and process. Based on library sources and employing a descriptive-analytical method, the present research addresses the investigation of these titles and epithets and why and how they changed. Finally, it resolves the question that there is a connection between the selection of these titles and epithets and some historical events of that time, through the sequence and order of which, it is possible to suggest dates for the minting of these coins.