Among various genres of epic, lyrical and dramatic literature, there is didactic literature which is very important and dates back to ancient times. Didactc literature is a bright sky that shines in the literary generes. Persian poets have tried to give advice and wisdom in their poems after the fourth century AH. Kasaee Marvzi and NaserKhosrow are among these poets. Ferdousi has also shown abundant attention to wisdom and sermons and after him AsadiTusi has brought religious, ethical, social teachings as well as contrivance, and civilization policy in Garshasbnameh, an epic text. In Garshasbnameh the number of wisdom and advice poems (didactic literature) is more outstanding than other ones such as epics, myth, and the combat of champions like Garshasb and Nariman, or the wonders of the land and sea. The present study attempts to show the didactic aspect of Garshasbnameh, as well as epic and myth aspects which are important and should be discussed. AsadiTusi has expressed some pieces of advices which they were under the influence of religious and advisory education of Islam. He has also elaborated on cultural heritage of ancient Iran which is proponent in his advices.