In order to obtain much more un-known actinomycetes for discovering new drug lead, one hundred soil samples were collected from five national natural protection areas of tropical rain forests, Mengla, Menglun, Mandian, Xiaomengyang and Guanping, in Xishuangbanna, Yunnan, China. 1652 purified cultures of actinobacteria were isolated from these samples by using 5 media. The 16S rRNA gene sequences of 388 selected strains were analyzed, and the phylogenetic analysis was carried out. 35 genera which belong to 8 orders and 14 families of the Class actinobacteria were identified. It is showed from research results that actinomycete diversity in tropical rain forest of Xishuangbanna is the highest comparing with all areas studied in our laboratories before. Selective isolation methods for un-known actinomycetes from soil samples, including medium and inhibitors are discussed in this paper.