Coins can be considered one of the most important artifacts of the Al Buwayhid (320-448 AH). In general, coins in addition to providing historical information about the place and year of mintage and the name of the kings, due to having an inscription, reflect the written forms of the time.  Due to the specialty of the alphabet in the formation and evolution of inscriptions in the fourth and fifth centuries AH, recognizing the writing forms of coins of this period is vital. The city of  Shiraz was one of the most important cities of the  Al Buwayhid regarding the mintage of coins. This study investigates the style of mintage coins in Shiraz and classifies the written form of the inscriptions of these coins. This research seeks to answer two questions based on the descriptive-analytical method: What features of the visual structure of the letters should be considered in the classification of these coins? What are the most important structural features of Shirazi mintage coins? This study identifies four main categories of writing on coins. In the first group, the alphabet on the coins was engraved with letters, in the second group, the letters were accompanied by decorative forms, in the third group, the letters were associated with the elongated letters, and the compression of the letters on the seat line. This group can be considered as a special group of Shirazi Mintage. The fourth group includes part of the third group and the ancient manuscripts.