According to the archaeologists and the works which were found around Kashafrud River, Khorasan province has an eight- hundred -thousand year background, therefore this province is one of the most ancient civilization centers. Khorasan in Parthian and Sassanians time was regarded as one of four great provinces of Iran- Apakhtar(North), Khorasan (East), Nimruz(South) and Khavaran(West), these divisions were protected in Islamic time. After conquering of the Muslims and the entrance of Islam into this land, Khorasan has had too much importance as a spiritual center of Iran and one of the sources of Persian literature. Many cultural political, literary and religious figures rose from this land.