Abstract During the last half century, rubber plantations have spread widely and rapidly in Xishuangbanna, China. This study characterizes the process of expansion in smallholder rubber farming and the subsequent changes in upland use through an in-depth case study of two Dai villages in Xishuangbanna. The results show that the area of smallholder rubber farming has increased in the study villages, as observed in other parts of Xishuangbanna. The evolution of forest policy governing the community forest in Xishuangbanna is divided into three periods: the initial, transition and strict control periods. In the initial period, customary law governed the community forest, and planting rubber was a risky choice in the eyes of villagers, while the government-provided subsidy and techniques spurred the conversion from subsistence cropping to rubber gardens. In the transition period, forest governance by the government began to intervene in the land use customs. Villagers recognized the profitability of rubber farming, and they had chance to convert community forests into rubber gardens because the forest policy was ambiguous. The expansion of rubber farming had a substantial impact on forest cover in the transition period, while the village communities conserved a part of community forest because they have a stake in conserving forest resource. In the strict control period, the government initiated a strict control, especially targeting logging. Consequently, even though there remains a strong demand for the expansion of rubber farms, the new lands chosen for rubber farms were areas in which other crops were already established. In conclusion, strict government governance with a clear objective and support from local communities has been sufficient to control the encroachment of smallholder rubber farming into natural forests in Xishuangbanna.