Abstract: According to changes of the land use stage, especially swidden cultivation, commercial plantation and natural biodiver-sity and agrobiodiversity in Xishuangbanna during the past 50 years, the paper explores the interrelationships between social eco-nomic development and biodiversity changes. The findings include; (l) land use stage is the linkage between social economic development and biodiversity change. The past 50 years is the fastest period and largest scale of biodiversity change in the history under the un - stability of land tenure policy, replacement of rubber of natural forest by state farm, expansion of community rubber plantation under the transition from central planning to market driven economic policy, which led to reduction and fragmentation of natural tropical forest, and caused decrease of natural biodiversity.

Key words: Xishuangbanna