By studying the niche characteristics of Cinnamomum population,this paper provided a theoretical basis for its population restoration and protection.Quantitative analysis method was used to study the niche of Cinnamomum and dominant species in 5 communities of Jianfengling mountain rainforest,the results show that:1)The greater the niche breadth of dominant species in the same community,the greater the adaptation range of species to ecological factors,which were widely distributed and more even in the community;However,the niche breadth of dominant species with high important value was not necessarily large.2)The niche width of Cinnamomum was above medium,indicatsing that it had stronger adaptability in mountain rainforests and mades full use of environmental resources.3)In regeneration forest community,Cinnamomum and thelight-loving dominant species had more intense competition,with the progress of succession,the intense degree of competition also gradually decreased.In the primeval forest community,the niche overlap of Cinnamomum and shade-tolerant tree species was greater,and had more similarities in resources utilization,which was often associated tree species in primary forest communities.