Abstract: The CTM(Continuous Time Markov Approach)model of Endangered Mechanism of Dioscorea nipponica Population, based on field data collected from San Chazi Forestry Bureau in Ji Lin, Songjiang River Forestry Bureau, Maoer Mountain Forest Field in Hei Longjiang and Liangshui Reserve Area, is constructed to make comparative analysis of evolution trend forecast with altitude of Dioscorea nipponica population and influenced extents of natural and artificial factors.Research results show that between 2 700~2 900 m, the population density of Dioscorea nipponica is relatively stable and grows very well while the states are worse in other areas.Affected by natural as well as artificial factors, Dioscorea nipponica population is endangered as a whole.However, the influencing cycle of each factor is different because some of them can be artificially controlled while other naturally occurred.The corresponding measurements of conserving endangered species are thus put forward.

Key words: Dioscorea nipponica, population, endanger, CTM Approach