The main goal of this research was classification of ecological groups and investigation of its relation with plants biodiversity indices in Afratakhteh reserved area. This study was conducted based on Brown- Blanquet method. At first homogen vegetation units were identified and then 41 sample plot (Releves) were selected selectively. The study of biodiversity indices was performed based on species cover data and use of current formula including Simpson and Shannon- Wieaner. For ecological groups classification and ordination, Two way indicator species analysis (TWINSPAN) and Canonical Correspondence Analysis (CCA) were performed respectively using Pc-ord for win. 4.17 software. Four ecological groups were distinguished on the basis of pesence-absence and cver of plant species. Then the relationship between releves distribution and biodiversity indices was investigated using CCA. The results showed that ecological groups are exactly different together in sepecies composition, biodiversity and physiography variables including elevation (A. S. L.), slope and geographic aspects. Result showed that the diversity and richness were decreased with increase of elevation and slope that causes more difficult life conditions.