The objective of current study was to investigative the population ecology of Macrobenthos of Gabrik Creek protected area in Jask city (Oman Sampling was conducted from autumn 2009 to summer 2010, by Van Veen Grab with area of 0/25 m2 and depth of 10 cm in three stations in Mouth, middle and end of creek). Enviromental parametrs consist of temperature, salinity, dissolved oxygen, turbility, electrical conductivity and pH, analysis of sediment texture and organic matter contents were also measured. The results showed that Bivalves were the most abundance with a percentage of 42 and Gastropoda, the lowest abundance with 10 percentage frequency of Macrobenthos was increased from mouth to the end of creek. In this study, 53 species belonging to 31 genera of Macrobenthos were identified and counted. The Results of ecological indicators was including Shannon Weiner (0.69±0.19), Simpson (0.19±0.15) and Margalef (17.39±8.51), respectively. According to the results, the frequency and diversity were decreased in hot seasons and the most important factor that affected these fluctuations was temperature. The results showed that in Jask protected area, a total of 53 species belonging to 31 families were identified. Macrobenthos of Mangrove forests has high diversity. Organic matter contents of bottom sediments were relatively high that was probably due to the sediment grain size that was silty-clay type.