Miankaleh Biosphere Reserve it has a set of marine and land ecosystems an area about 67349 ha and is located in the north of Iran and Southeast farthermost of Caspian Sea. The diversity of the natural characteristics of Caspian region is the cause of diversity in the habitats, and has resulted in nesting of most plant species in the germinative range. Regarding the importance of coastal ecosystem of Miankaleh Biosphere Reserve as a sub region of southern Caspian Sea it is necessary to consider and investigate the role of ecological factors and their effects in the variance and diversity of the plant species. For this purpose this research has been conducted to identify the coastal plants and the effect of their geographical distributions and life forms; the effect of various environmental factors (slope, exposition, some chemical properties of soils) on the vegetation and determination of most effective environmental characteristics in their estabilishment is also studied. Plant diversity, habitat and environmental characteristics have been evaluated through three transects using TWINSPAN rating technique, DCA rating analysis and ANOVA analysis. In order to investigating the significancy and not-significancy of these results, the results obtained from DCA rating analysis have been assessed through conducting some accurate tests. In this study, six habitats along with eight Ecological species groups for the 314 species in the investigated area were identified .EC and pH in soils were the most important effective factors on the settlement of vegetations in different regions, respectively.
