Abstract: The rare endangered plant Ammopiptanthus nanus is a kind of evergreen broadleaved shrub endemic to the desert in the central part of Asia. It is only distributed in Kezilesu Kirgiz Autonomous Prefecture of Xinjiang and the Soviet Union. Now the plant is under the second-grade protection of the state and the first-grade in Xinjiang.Through the field investigation on Ammopiptanthus nanus and in the light of the climate conditions in the range, this paper analysed temperature, illumination,moisture and soil in the ecological environments. The vulnerable reasons of the plant was studied.As a result of analysis and study, the bioecological characteristics of Ammopiptanthus nanus have been found preliminarily as follows: Cold resistant,heat resistant and tolerant to wide range of temperature variation, light demanding with some features of shade preference, drought resistante, and fairly salinization resistant.The vulnerabling of the plant can be attributed to: 1. Special shape of the seed which makes the seeds difficult to spread and to get the suitable conditions for growth. 2. Prone to pests. 3. Upplaned cutting of the plant for firewood.In view of the above results, we suggested the conservation should be started at once, besides, nature reserver supported with necessary protective measures must be established as soon as possible.