This article take ”the brother first ancestor myth and legends in Taiwan aborigines”, which generally spreads in Taiwan, as the discussion object, By the survey of these myth and legends, We discovered that these narratives not only is the people's historical experience and the ethnic group collective memories, but also may reflect the complex origins of the peoples, and the multicultural ethnic relationships in Taiwan aborigines. On the other hand, By this kind of narratives, We would like to discuss the borderline between ”imagination” and ”history”, and ”myth” and ”reality”, and reconsidered the view that regard the myth and legends as fictionalized or imagination in the past. I thought that a lot of oral literature that spread in the Taiwan aborigines generally, not only may provide a bigger space for the historical explanation, but also may administered the important reference to make a survey of the history and culture of Taiwan various ethnic groups, and the development and the transitionary course.