is a heroic epic that was sung before the 8th century in Tibet. In the early Tibetan dynasty(around 581-753), Bönpo was accepted as the national religion and Bönpo believers participated in the government through folklore including historic poems. Then khri-sroṅ-lde-btsan(enthroned in 754) imported Buddhism as the national religion from India in 761 but as the Tibetan dynasty was divided into the south and the north Glaṅ Dharma executed anti-Buddhist policies and the Tibetan Buddhism confronted a crisis. From the mid 10th century, Buddhism revived and from the 11th century written began to emerge. The written volumes were usually published by the noble literati or monks, and those published by noble monks were saturated with Buddhism. The emergency of written saturated with Buddhism was mainly for Buddhism to hold a dominant position over Bönpo and, by doing so, to strengthen its political influence. In general oral heroic epics based on a religion cast off the religiousness over time but Tibetan is peculiar in that it replaced its original religion with another. In addition, as it was switched from an oral tradition to a written work, it revealed the firm intention to propagate Buddhism. Nevertheless, the oral heroic epic did not disappear in Tibet. It was because of its shamanistic nature. In this point, the Buddhism-oriented is the same. It was because Indian Buddhism imported to Tibet had an esoteric nature. In this sense, Tibetan can be regarded as a heroic epic categorized into a ritual epic.