Abstract: The aim of this study was to investigate the biodiversity and richness of vegetation between ecological species group. In this research, vegetation (tree, shrub, bush and herbaceous species), Persian Oak (Quercus brantii) natural regeneration, some physical and chemical properties of soil and physiographic factors were taken in 50 sample plots. The plots area was 20x20 m. The sample plots were located using transect`s method. The coverage percent of trees and shrubs in each plot were measured regarding to large and small canopy diameter. For herbaceous layer, Withaker, hasted plot sampling was used and 64 m2 were defined as minimal area. Overall, 4 trees, 3 shrubs, 1 bush and 78 herbaceous species, which belong to 73 genera and 32 families, were recognized. Multivariate analysis methods were used to classify and determine the relationship between species composition and environmental factors and also to recognize ecological species group. The results indicated that five ecological species groups were recognized in the study area and the parameters such as: elevation, organic matter, N, P, K, bulk density, SP, pH, clay and C/N were important factors. The results indicated that biodiversity and richness were maximum in the third group. This site was more humid than the others and organic materials such as, N, P and K are higher than the other sites. In the fifth group that bulk density was high and organic matters were low and its soil was compacted, biodiversity and richness were lower than the other groups.