Cil is one of the small local groups of the Coho, which belongs to Mon-Khmer language group in Vietnam. The Cil’s society is matrilineal and the village is comprised of small units with only 2-3 houses. Their major source of income is maize cultivation using slash-and-burn farming and shifting cultivation. Because of historical changes like the Western colonial era-French Indochina, the Vietnam war, socialist policy, and renovation, their economy base now is crop production, particularly persimmon, coffee, lowland/wet rice, and working as employees. Most of the villages have been divided and absorbed by some administrative hamlets.
This paper assesses the Cil’s social structure, based on cross cousin marriage alliances and gift-giving during ceremonies. In addition, this paper looks into the changes in range of marriage partner with historical changes and the proposal for the expansion of the marriage alliance model used by Cil in order to obtain land use rights.