The author studied the culture, particularly social life, of a tribal society of the Kabar plain in the inland area of the Kepala Burung (Vogelkop) in Irian Jaya. The focus was on constants, variants, and changes in the field of kinship and religion. Ch. 1 gives a historical survey of the Kabar plain. Ch. 2 pays attention to environment and demographic data. To determine the influences of processes of state formation in the East Indonesian archipelago on theKebar, chapters 3 and 4 look at the intra- and intertribal (kinship) relations, including changes occurring in them, and the Kebar man- and worldview. Ch. 5 discusses the connection between social historical and ecological influences on the culture of the Kebar, in particular in the fields of kinship and religion.