Due to its geographical location and historical reasons, the land of Iran has long been a place for accepting different ethnicities, religions and cultures. In this regard, the followers of Judaism and Christianity at some point in time made Iran a safe place to live. According to sources, with the coming to power of the Sassanids and the proclamation of Zoroastrianism as the official religion of the country, restrictions arose for the followers of the religions living in the empire.Our knowledge of the situation of Sassanid Jews and Christians is based on parts of the Talmud, Sassanid inscriptions, works by Armenian, Syriac, and Islamic writers, which, in addition to limited information, contain one-sided and sometimes untrue accounts of Sassanid treatment of non-Zoroastrians. . This study, using library resources and descriptive-analytical method, intends to find an answer to the question of what were the factors of the situation of Jews and Christians in the Sassanid and can only the religious factor be considered effective?Application of policies and religious tendencies of some Sassanid kings, influence of Zoroastrian clerics, recognition of Christianity in the Eastern Roman Empire, rivalry and enmity between followers of different religions for power, financial reasons, rivalry and enmity between the Roman and Iran are important factors and It affects the situation of religious minorities living in the Sassanid borders. Nevertheless, Jews and Christians, as part of the human and economic resources of the government, played an important role in Sassanid society and, despite their one-sided views, interacted with the Sassanid , except in cases and moments, so re-reading critically and away from prejudice. Existing sources and narrations seem necessary.