The stand structure and plant diversity of Liuxihe National Forest Park were discussed,so as to provide theoretical basis for forest management and plant diversity protection of its natural secondary broad-leaved mixed forest.The results showed that:1) Liuxihe National Forest Park had higher plant diversity and stronger natural regeneration ability.Single-species family composition of tree species and understory plants were 50% or more.There were quite more species and quantity of seedlings,and the natural regeneration ability of stands was strong,but young trees were relatively few.2) There were big differences in stand canopy density,stem density and DBH,and the spatial layout of trees needed to be adjusted.In sample-plots,the canopy density was 0.64~0.90,and the stem density was 675~1 975 plants per hectare,and the DBH was between 5.0~44.5 centimeter.The spatial distribution of stands was mainly in the form of clusters,and the forest competition was medium.3) The plant diversity of arbor layer was rich,and that of shrub layer was affected by stand factors.In different forest layers,the four indexes of arbor layer were relatively high.The shrub layer was affected by stand factors such as canopy density and mean DBH,and the herb layer was basically unaffected,and the sapling and seedling layer were affected by canopy density.Therefore,forest tending and thinning should be carried out,and stand density and spatial distribution of trees should be appropriately adjusted.The quantity and quality of saplings and seedlings should be improved,and understory shrub species should be enriched.The diversity and stability of plant community should be improved in Liuxihe National Forest Park,to ensure the sustainable and stable development of forests.