AbstractNinety-two bottom surface sediment samples were collected in the Guanabara bay using a van-Veen sampler. They were analyzed for grain size distribution and organic matter. From the association between the bottom morphology and sediment characteristics, it was possible to establish the sedimentary dynamics. This allowed a division of the bight into three sedimentary zones: a south, sand-dominated zone of relatively high wave and current energy, a north zone characterized by very calm conditions and clay/mud deposition, and a central zone of mixed sedimentary characteristics.Palavras-chaves: Sediment Dynamic, Guanabara Bay, Texture