The Seediq and Truku tribes of Taiwanese Aborigines, in spite of being politically independent, are of high homogeneity in terms of languages and cultures, which constantly results in dispute on tribal identification. This thesis provides an academic research to deal with this issue, that is, to activate a systematic analysis on the music of both tribes and furthermore, comparing their musical homogeneity and differentiality for the purpose of offering meaningful data of ethnic identification.This thesis is based on the information gathered from field investigation took in 2005-07 by the author. The results include 164 video and audio recordings and the task of phonetic transcription, translation and interpretation of the texts, and musical transcription has also been finished.After the completion of data collection, the process of "Categorizing- Analyzing- Summarizing" is undertaken. In the step of categorizing, the "Song Types" and "Melody Types" of the entire repertoire are distinguished from the aspect of lyrics and melodies. In Analyzing step, various theoretical approaches are induced- including the theories of music semiotics proposed by Jean-Jacques Nattiez, Schenkerian Analysis formed by Heinrich Schenker, and John Blacking's functionalistic analytical approach-in order to analyze the fundamental vocabularies of tribal music. Then, in the step of summarizing, the function, meaning, the inner functional structures of respective tribal music, are summarized.In the final stage of this thesis, the author interprets the meaning of inner functional structures of music of each tribe from the functionalistic angle of Blacking. The fact that these two tribes are closely linked to each other in blood and in culture is based on the evidence of both tribal music systems being constructed on the tetrachord "re, mi, sol, la". However, as the result of long-term separation, minor discrepancies gradually emerge, which corresponds to the analytical result of function : "la-mi-sol-mi" for Seediq tribe and "sol-mi-la-mi" for Truku tribe. These fundamental music structures do exist and dominate the musical behavior and melodic structures of respective tribal music system. Ultimately, the result of this research confirms the academic conclusion proposed by John Blacking as "The music style of a specific tribe is the symbolic representation of its own cultural aspects".