The Amis are distributed in the Taitung longitudinal valley and on eastern coastal plains. With a population of 138,000, they are the largest of all the Formosan aboriginal tribes. The Amis can be subdivided into five groups from north to south: the Nanshih, Hsiukuluan, Coastal, Peinan, and Hengchun groups. These Amis communities are mostly scattered on the plains, close to the sea and along river banks.
Unlike other tribes, the Amis are characterized by matriarchy and a male hierarchy determined by age. These are two key elements in maintaining a balanced distribution of labor and power among men and women. The male hierarchy underscores reverence for the elderly and stresses obedience. The chieftain and senior tribal members work together on deciding village affairs, and villagers are assigned different duties according to their age. The younger are required to undertake a larger portion of menial labor.
The harvest festival, generally held in every village in July or August, used to be a military exercise designed to only play minor role in the harvest festival, which actually highlights athletic contests, fishing at sea, and several days devoted to singing and dancing in celebration.