Sassanid rule in the period between 224-651 AD in the Late Holocene; Two climatic events show the Roman warm period (MWP) and the Cold period of Migration time (EMC). Identifying the conditions and climate changes of the Sassanid period, the challenges and reactions of the Sassanid government and society to these events is the main goal of the research. Iran has been more humid during warm events than cold events. In the period of these two weather events, fluctuations are observed. Climatic changes in different regions and latitudes of Iran have a time difference with Northern Europe. This time difference is noticeable in southern Iran. The warm Roman period occurred in the south of Iran in the approximate period of 0-750 and the Cold period of migration time did not occur in the south of Iran. Climatic changes, especially droughts, for the Sassanid government, which had an economy based on agriculture and trade; It caused challenges such as the invasion and migration of different tribes to Iran's borders, the Mazdak movement, and the outbreak of disease. In addition to the climatic changes in the interior regions of Iran, the climatic changes in other regions such as Central Asia, Rome and other neighboring regions have influenced the political-social-cultural events of the Sassanid. The Sassanid period shows an increase in settlement compared to the Parthian and Islamic periods. This increase in settlement becomes more important due to the more climatic tensions of the Sassanid compared to the Parthian era and the early Islamic centuries. The response of Sassanid government and society to climate changes can be identified in archaeological data and historical texts. Among them are the appearance of the goddess Anahita, changes in Sasanian coins, the development of hydraulic systems, especially the construction of dams and aqueducts in different regions of Iran, the construction of defensive walls, and the economic reforms of Khosrow Anoushirvan
