Abstract: During 2010－2014, sample plots were established under rubber stands in Dai Autonomous Prefecture of Xishuangbanna, Yunnan province, for investigation of medicinal plant resources. Analysis was made on composition, life forms, medical part and functions of medicinal plants. The result demonstrated that there were 364 species of medicinal plants, belonging to 267 genera and 92 families, most of them were herbs, about 45.60% of the total. Their medical parts such as the total plant, root, leaf, etc. could be classified into 9 types, that of total plant accounted 45.88% of medicinal plants. Medical function of investigated plants could be grouped into 15, like relieving exterior syndrome, detoxification, relieving swelling and pain, etc. 34 species of 33 genera and 29 families of medicinal plants were listed in the Chinese Pharmacopoeia, which occupied 9.34%, 12.31% and 31.52% of the total species, genera and families under rubber forests.