The old, rich and popular tradition of verbal story-telling, carried out by narrators, has been prevalent among all Indo-Europeans, especially, Aryan races inhabited the Iranian plateau, east of Iran and large khorasan. It had saved ancient myths , fictions and also historical events and had transmitted them to us. In this article, we will try to evaluate this tradition historically, and show that most of fictions, stories and mythological works in Islamic era have been formed under the influence of this verbal tradition.Many parts of Shahname, Samak-e-ayyar and Abumoslemname had been narrated by narrators and then written down. By a morphological comparison among Shahname, Samak-e-ayyar and Abumosslemname not only has proved this fact but also revealed that Samak-e-ayyar is an epic, not a fiction and Abumosslemname is a national epic, not historical one.Finally we have showed that, after Shahname, this tradition and its works have been transmitted, first by motivations other than patriotism such as amusement and earning money, secondly fallen into decline of content and vulgarity (popularity). As a result, its path was separated from formal literature, and its addressees altered, and some non-epical motives entered into this tradition