This study investigates the traditional textile patterns of the Atayal people, one of Taiwan’s indigenous groups, by comparing samples, analyzing visual elements, and examining geographical subgroup distribution. The findings reveal that, despite differences in location, many Atayal subgroups share common geometric patterns—such as diamonds, mountains, and crosses—which often symbolize ancestral beliefs and ethnic identity. Due to technical limitations in weaving, similar structural motifs emerged across groups. The most frequently used colors are black, white, and red, although each subgroup exhibits distinct color preferences. Pattern structures often form complex stripe compositions, featuring high levels of repetition, reflection, and modular design, resembling a form of pattern database. Migration, cultural interaction, and the introduction of new materials and dyes have influenced the evolution of Atayal textiles, though their geometric essence remains largely preserved. Fieldwork initially proved insufficient for collecting usable samples, leading the researcher to turn to museum collections. By combining methods from visual communication design and anthropology, the study proposes a multidisciplinary framework for pattern analysis. This research lays the groundwork for future studies on the traditional garments of other Taiwanese indigenous groups.