Abstract: Ulan Buh Desert is situated at the transition zone between wilderness area and the prairie area in Asia. There is an important phytogeography boundary. Study on the desert plant diversity was carried out around Ulan Buh Desert region. Preliminary results are as follows: there are 312 native plant species and the abundance of their diversity is richer than that in other desert regions in Northwest China. The plant geographical compositions are mainly composed of the species of the ancient Mediterranean,the Middle Asia and Mongolia Gobi ect. The shrub and half-shrub species of xerophyte,halophyte and arenicolous plant take the superiority and they have 11 life types of flora diversity. The correlation between the local and neighboring flora areas is close and extensive. Based on the analysis on the reasons of the loss of the desert plant diversity,this article proposed ecologyical countermeasure of promoting the sustainable development of and conservation of desert plant diversity in the pastoral area and oasis.

Key words: Ulan Buh Desert region, desert plant diversity, protection