Abstract: 24 species and 4 varietes of genus Stipa L. of China have been studied and described in this paper. It has been noted that these different species have various geographical distributions, depending on the changes of climatic and edaphic factors of their environments. Based on the study of floral morphology together with ecological and distributional factors, the genus have been divided into 5 sections: 1. Sect. Regelia Tzvel. 2. Sect. Leiostipa Dum. 3. Sect. Barbatae Junge 4. Sect. Stipa 5. Sect. Smirnovia Tzvel. It should be pointed out that the section Regelia as well as two members of section Barbatae, S. purpurea and S. roborowskyi, belong to frigori-xerophilous ecotype, distributing over Qinghai-Xizang Plateau above the forest line. The section Leiostipa belongs to euxerophilous and mesoxerophilous ecotype, distributing widely in northwest, southwest, northeast and east and extends to the forest-steppe vegetational Zone of China. The section Smirnovia and other two members of section Barbatae, S. breviflora and S. orientalis, belong to euxerophilous ecotype, with the latitudinal distribution as far as Nei-Mongo and the yellow soil plateau, with the altitudinal distribution as far as the desert steppe of Sinkang and Qinghai-Xizang plateau. The section Stipa belongs to euxerophilous ecotype, only distributes to the mountain steppe of north Xingkang and the last, section Barbatae is an artificial group having plumes overof the awn only, and its four species have already been mentioned above.