There are two aims in this paper: one is to present the types and themes of the myth of origin and the legend of distribution of Ami society; the other is to discuss the affinities among the Ami subgroups through the comparison of their myth, legend, language, as well as genetic distances of ABO blood groups. Making a comparison among the myth and legend of the Ami subgroups, we find that the types of mythology of the northern and the central subgroups are closer that that of the southern one, This tentative result is also supported by the data of ABO blood groups of Ami people. The genetic distances of ABO blood groups between the central and the northern subgroups are shorter than that to be compared with the Peinan-Ami, part of the southern subgroup. And according to the lexican analysis of Ami dialects, part of the central dialectal groups is near the northern group, however another is near the southern group. Moreover, with the analysis of the phonetic system, the primitive feature on the northern Ami dialect is another important point need to be considered. With the above analyses, we tentatively make the following conclusions: first, since the northern Ami has the most primitive feature on its phonetic system, therefore it might be able to refer that this subgroup could be the earliest Ami society in Taiwan. Afterwards, some of the northern Ami people might have extended southward and interacted with the central Ami frequently and closely, that is why there are obvious affinities between the northern and the central Ami subgroups on the myth, legend, and blood groups distributions. However, in contrast with the other two Ami subgroups, the southern Ami owns the most specific features on its myth, legend, and blood groups. One of the reasons raised here is that since the seventeenth century, the southern Ami might have interacted more closely with its neighbouring Puyuma tribes (another indigenous people living in south-eastern coast of Taiwan) than with other Ami subgroups.