In this article, the classes of Sasanian society are examined in two main categories: the Middle Persian literary sources and the sources of the Islamic period, and the characteristics of each class are stated by comparing the historical sources after Islam. Also, showing the diversity of the sources and their classification was the opinion of the authors of the article. Most researchers who have studied the history of the Sassanids usually devote a part of their research results to discussing the classes of Sassanid society. A brief look at these writings gives the impression that most of the research in this field is based on the famous and valuable work of the Danish orientalist Arthur Emanuel Christensen, Iran during the Sassanid Period, and their reports of their results do not provide anything beyond what Christensen said. A prominent feature and at the same time a shortcoming of such research, in which Christensen's line is followed, is that the information obtained from the sources is put together in a traditional way and a superficial and seemingly coherent description of the classes is presented. However, by examining the original sources (Middle Persian manuscripts and Islamic sources from the third to seventh centuries AH), on the one hand, a kind of confusion in the arrangement of the classes is observed, and on the other hand, important characteristics and details