Taiwan's indigenous people have rich oral mythos. In which the type of flood-rebirth myth belongs to one kind of the worldwide story type. In this article, we decompose the plot units of its 41 texts and divide them into two subtypes. The subtype I takes the Algerian-US race as representative, the subtype II takes the Sai-xia race as representative. Comparing with the same type myth of the mainland, we find that the plot skeleton of subtype I is quite similar with the two language branches of Miao-Yao and Tibeto-Burman, but not so as the in variable motif. Besides these we have compared the type flood-rebirth myth in both banks of Taiwan Straits with 7 similarities and differences. Through studying we think that these ethnic memories will provide the clues to reveal the friend or stranger relations between nationalities.