Mountains at high altitudes offer an ideal system for examining biological and abiotic factors in community assembly processes,given the significant environmental variations.The effects of different altitudinal gradients on species diversity,functional diversity and lineage diversity of mammals were analyzed in order to understand the construction process of mammal community at high altitude. We carried out a one-year survey in Haba Snow Mountain,Yunnan Province. A total of 6 300m altitude belts,62 infrared cameras,24 clip lines,and 24 fence traps were deployed. A total of 2155 valid mammal photos,5150 clip days,108 trap days. A total of 41 species of mammals were recorded,belonging to 8 orders and 24 families. The results showed that species richness peaked in the 3100-3400m altitude zone,with no significant differences in the Simpson,Shannon,and Pielou indices across different altitudinal gradients(P < 0.05).There was no significant difference in the species composition of mammals under the altitude gradient,and the species composition structure was similar and the separation was not obvious. Functional diversity declined with altitude gain,and functional richness in the < 2500m altitude zone and 2500-2800m altitude zone was significantly higher compared to other altitude zones (P < 0.05). The functional space size and space utilization degree occupied by species in these two altitude zones were significantly higher than those in other altitude zones. The regression analysis of species diversity and functional diversity showed that the increase of species diversity index led to the increase of functional richness,functional dispersion and functional differentiation,but did not change the change of functional evenness index. The standardized effect size analysis showed that there was a tendency of mammal aggregation in the < 2500m altitude zone,and habitat filtering dominated the construction of mammal community. In the other elevations,there was a tendency of dispersion,and competitive exclusion dominated the construction of mammalian communities. The results show that the diverse environment of Haba Snow Mountain provides strong support for maintaining high mammal community diversity in the region,and it is important to consider multiple biodiversity indicators when assessing community structure.