Abstract: The rare and endangered plant Ammopiptanthus mongolicus is a kind of evergreen broadleaved shrub endemic to the desert in Alashan.Now the plant is under the third-grade priority protection of the state and the second-grade in Inner Mongolia.This paper deals with temperature, illumination, moisture and soil in the ecological environment in the distribution region of Ammopiptanthus mongolicus, and has made experiments in seeds of germinating.As a result of analysis and study, the declining reasons of the endangered plant, such as climatic and geological changes, human-related activities, as well as the rareness of falling seeds capable of germinating, and the difficulty for the seeds to get the suitable conditions to gowth have been found.In view of the above results, we suggested the conservation should be started at once, besides, some measures for effectively preserving this species are proposed.

Key words: Ammopiptanthus mongolicus, Endangered factors