This paper investigates changes in land cover, land-tenure policies, and market pressures in Baka village, Yunnan Province, China. Before 1950 local farmers engaged in many forms of collective behavior including common property management, religious rites, and other activities led by clan leaders. Between 1950 and 1978 peoples' communes governed the management of most lands. All farming activities were organized, and the amount of land to be farmed was determined according to instructions from upper administration levels. The implementation of the Household Responsibility System after 1979 gave individual households greater incentives to produce cash crops. These changes caused a demise in the planting of traditional crops, increased differentiation between rich and poor, and a gradual decline in collective forms of land management.