The article discusses subjective issues in Oral History. Oral History, as a modem and different way of record's creation has been brought about new horizons in recent decades. In this method of capturing historical events, People are equally Provided with Opportunities to transfer their experiences. In this way, records Production steps outside official track, and covers ordinary People as well. Although, the Process is deeply rooted in our chronology, especially in Islamic Period, this has been heeded rarely in modern dialog. New Productions of this chronology method have made their way gradually among other records, however, discussions on reasons of the new method have not been looked into sufficiently. Therefore, the Paper examines the Precedents of the chronology, Oral History and its significance on the one hand, and on the other, reviews the level of credibility, considered for Oral records and ultimately Oral History.