The structure of the benthic amphipod assemblage and its relationship with soft-bottom characteristics (particle size, organic matter, etc.) of the coastal waters at the depths of 0-5 m at the Dardanelles, including the Turkish Straits System, was studied. A SCUBA diver took benthos and sediment samples seasonally using a quadrate system of 30x30 cm as three transects from the 8 different stations between July 2008 and April 2009. A total of 3007 individuals belonging to 50 species was reported. Among these, Corophium acutum Chevreux, 1908 had the highest dominance value (Di%=22.18) and the lowest dominance value belonged to Dexamine thea Boeck, 1861 (Di%=0.03). The highest positive correlation (r(s)=0.57, p < 0.05) was observed between the gravel content (%) and the abundance (ind. m(-2)). The highest sand rate (99.59%) in the sediment was found at the Eceabat site. The lowest rate was at the Kepez Harbour station with a value of 73.01%. The highest H' value (1.53) was recorded at the Eceabat site, and the lowest H' value (H'=0.95) was recorded at the Gallipoli sampling station.