Abstract: Based on the investigation data collected from natural of Cystonathyrium Chinese populations in three natural plots,studies were made of the niche breadth values, niche similarity values and niche overlap values of the main herb species in the plant community of Cystonathyrium Chinese by the method of quantitative analysis. The results showed that niche width of C.chinese was comparatively high; it was disjunctive distribution in the subordinate status of their community.The niche overlap between populations was in the high degree.Their relationship was complex, and the sharing of resources was evident. Based on analysis of their endangered reasons,their own poor reproductive capacity and the deteriorating habitant condition were probably the main reasons of their endangerment.