The study of the role of the Ansar scholars in religious sciences in Khorasan and the country beyond the river ( from the third century AH until the end of the seventh century AH / ninth century to thirteenth century AD) is one of the important topics, if they contributed in the fields of science and religious knowledge, and we find among them knowledge in readings, interpretation, hadith, jurisprudence and mysticism, and some of them assumed jobs such as fatwa, judiciary and teaching in mosques and others.The scholars of the Ansar were interested in religious sciences, and we referred to their sheikhs, students, works, news, journeys, attributes and efforts in spreading knowledge with mentioning their lineage, historical roots , tribes , and titles , emphasizing the years of their birth , death, homes , news of their famous figures and celebrities .The research was divided into an introduction and a preface in terms of the geographical location of Khorasan and Transoxiana. The scholars were also divided according to religious sciences in terms of the science of readings, interpretation, hadith, jurisprudence, and theology, as well as Sufism.