Daxing'anling Mts.are the most important cold-temperate taiga forests in China.By taking Huzhong National Reserve,as the study objective,we investigated trees,shrubs and herbs by the field plot method,and calculated plant diversity indices,then performed redundancy ordination of their association and found that,Larix gmelinii was the main tree species in the arbor layer,with a relative abundance of 80.39%,followed by Betula platyphylla. The proportion of lingonberry (Vaccinium Vitis-Idaea) was the highest among shrubs,reaching 87.85%.A total of 51 species of herbs layer were found,of which Deyeuxia angustifolia accounted for the largest proportion,reaching 37.85%.Larix gmelinii was the main tree species in the regeneration layer with the relative abundance of 77.94%,and the rest was Betula platyphylla.Redundancy ordination and variance partitioning analysis showed that the independent effect of community structure and shrub layer characteristics contributed the most to the diversity change,and shrub coverage,ground diameter of regeneration layer and shrub density had the closest relationship with plant diversity change,and the protection of plant diversity can be achieved by adjusting the above factors with fully accounting of the impact of other community structure characteristics of arbor,shrub and herbs on species diversity.