Based on particle settling observations of muddy sediment samples from the Changjiang Estuary, the influence of water temperature on muddy sediment deposition was investigated. For water temperatures less than 25°C, mud particles are preferentially not flocculated but deposited as single grains. Under these conditions deposition is limited. When the water temperature exceeds 25°C, and given ... [Show full abstract] favorable salinity, ambient water velocity, grain size, and sediment concentration, the phenomenon of flocculation occurs, resulting in deposition of large amounts of mud particles. From these results, and based on water temperature records in the Changjiang Estuary, it is surmised that mud sediment deposition is favoured in summer when water temperatures exceed 25°C. This seasonal phenomenon presumably affects the patterns of erosion and deposition on the Changjiang estuary bed.