Bidkhun creek is located in the southern coasts of the Bushehr province, as a part of Nayband Bay. South Pars Economic and Energy Zone and related industrial establishments has surrounded the habitat. Discharge of swages from refinery phases, invasion of reeds, reduction of trees coverage and change of natural appearance in some places, reveal the hypothesis of degradation in environmental status of the ecosystem. Present study has been carried out to evaluate the ecological and environmental status of Bidkhun mangrove swamp. Sampling was performed in four seasons from winter 2013 to autumn 2014. Environmental parameters (temperature, salinity, pH, Eh and TOC), specification of surface sediment texture, macrofauna structure, water nutrients, heavy metals (Fe, Al, Cr, Pb, Zn, Cu, As, Ni and V) and Poly Aromatic Hydrocarbons (PAH’s) were investigated. Ecological indices; Sahnnon-Wiener, Simpson, AMBI and M-AMBI have been used to evaluate the environmental and ecological status of the habitat. Totally, 35 macrofauna species belong to 27 families, 20 orders and six clases were identified. Polycheata and gastropoda with ten and nine species were the dominant classes, respectively. There were spatial and temporal changes in macrofauna community structure. Sediment grain size and salinity were the most important environmental parameters which affected the spatial structure changes of macrofauna communities. Total Organic Carbon (TOC) and temperature were important factors that infuenced temporal changes in macrofauna community structure. The lowest density and abundance of macrofauna were observed in northern part of the habitat, in station four. Macrofauna in this station declined to zero in summer and autumn. Ecological indices show “Very Bad Ecologcal Status’ in station four and “Good Status” in other stations. Consideration of nutrients in sewages and marine waters illustrates discharge of high amount of nutrients, especially ammonia to the station four. High concentra