The relationships among the vertical layers (tree-,shrub- and herb-layer) of a temperate forest and the power of environmental and spatial factors were investigated to explain the variation in two attributes of herb-layer:cover and diversity.In the 1.0 hm ² study site,a total of 100 1-m ² sub-plots (each 20 m×20 m has 4 1-m ² sub-plots) were monitored monthly from May to September in 2009.Among the environmental factors,tree-and shrub-layer related factors (density,canopy cover and Shannon-diversity),soil attributes (soil organic matter,available nitrogen,available phosphorus,available potassium,soil water and pH) and light regime (LAI,PPFD and canopy presence) were studied.The results showed that:(1)The herbaceous composition varied over the growing season,Anemone amurensis and Corydalis ambigua dominating in May;and spring bloomers,early-summer bloomers and late-summer bloomers co-occurring in June,leading to species richness the highest;summer bloomers reaching their flourishing season in July,Shannon diversity index is the highest,from August to September,summer bloomers withered gradually.(2)The relationship between diversity of the shrub-layer and diversity in the herb-layer was positive,although non-significant relationship was found between tree-layer and herb-layer,and density of shrub-layer positively correlated with cover of herb-layer in some months and negatively correlated with diversity of herb-layer.(3)The relationship between cover and diversity of herb-layer with soil attributes,light regime,tree- and shrub-layer showed that available potassium,light regime and soil water content were key factors for linking the two strata.It was concluded that the diversity pattern was influenced by light,throughfall and litter amounts,which fluctuate with canopy density.