Abstract: By understanding the ecological relationship between Moso bamboo and the associated tree species in bamboo broadleaved mixed forest, this paper aims to find the appropriate proportion of cropping to provide basis for the optimization of the mixed forest from the niche level. A field plot sampling method was employed to investigate community niche of bamboo broadleaved mixed forest in Tianbaoyan of Fujian Province of Southern China. The Levins and Shaanon niche breadth index, niche overlap index, Schoener niche similarity index were used to study and analyze the niche characteristics of the tree layer and the regeneration layer with different mixing ratio of bamboo and broadleaved mixed forest as different resource niche. Results showed that: 1) the Levins and Shaanon niche breadth index showed that Castanopsis carlesii, Castanopsis fargesii and Alniphyllumfortunei were the dominant species of Moso bamboo, and their important value and niche breadth were strong, and the ecological adaptability was strong, and they play an important role in the change of community structure. 2) The ratio of niche similarity between tree species and the niche overlap index of Moso bamboo were not high. The L_hi value of Castanopsis fargesii was 0.509, and the L_hi value of the other species was less than 0.5, indicating that there was a large ecological difference between Moso bamboo and most tree species and resource utilization differences, and a stable symbiotic relationship was formed between each other. 3) The niche breadth of the evergreen tree species was larger than that of the deciduous tree species, and the niche overlap of Moso bamboo was relatively large. When the resource used by Moso bamboo was insufficient, it was also more likely to cause potential competition. 4) The density and biomass of Moso bamboo were the largest when the mixed ratio of bamboo and broadleaved mixed forest was in the range of 15%-20%. When the mixing ratio was too large, the bamboo gradually lost the dominant position in the community, and the symbiotic synergistic relationship with the broadleaved tree was more likely change to the competitive relationship.