The basic kin group of the Atayal society is the family called kutux ŋasan The ideal type of the Atayal family is a nuclear family which consists of the spouses and their unmarried children. The extended family not uncommon but usually considered as a transitional form. The following chart shows the family formation in the villages of Nan-ao and Chin-yang.

　　Among the Atayal society a family is a productive and consuming unit. The residential rule of the family reveals a definit trend toward patrilocality, but matrilocal residence appears when the family has no male successor and where the family has a large amount of land and other properties. The rule of inheritance tends to be patrilineal and follows primogeniture, but some variations happen depending upon the choice of residence and other factors.

　　Beyond the family circle, three kinds of kin are usually recognized and serve the functions of exogamy, productive labor and various life rituals. These are: kulux ßegis, consisting of all ego's relatives reckoning through great-great-grandfather; kulux gəlu, including the relatives above mentioned and the relatives reckoning through ego's great grandmother; kutux ganik, including two categories of kins said above and the affinal kins. This vague definition of the kinship structure has caused the Atayal society to lay emphasis on the functioning of the local groupings on one side and the ritual group on the other.

　　The Nan-ao Atayal live in relatively compact villages. A village or kalaŋ which is located mostly on a terrace or mountain slope is an autonomous unit in the political sense and the authority of the village is exercised chiefly by a village headman. The village chief is elected among the leaders of the local ritual groups because of his personal character and knowledge on productive and ritual affairs. The village of drainage basin or along a river are loosely organized into a village confederation which is organized in order to carry out their military adventures and therefore is always headed by one of the village chiefs who has distinguished himself in the head-hunting warfare. Before the move down to the delta region, 13 Nan-ao Atayal villages constituted the confederation called kutux lelioŋ kələsan and which had further been divided into three sub-confederations according to branches of the main river.

　　Within the organization of village level, the ritual group gaga which derives its members based on kin tie, local bound and friendship is the most important social unit in the prossession of full function. By means of ceremonial performance the gaga secures the guardianship for, or the damnation of their enterprises from the the ancestral spirits and secures mutual cooperation and assistance. The important of the ritual group will be come more clear after our discussion of their religious concepts and behaviors in the next section.