This study on the evolution of geomorphology and hydrodynamics in Fengche Creek at Jianggang Saltmarsh, Jiangsu showed that the geomorphologic development of Fengche Creek was mainly controlled by the hydrodynamics. The measured tidal current velocity in the creek in 1996 was only half of that in 1979. The creek bottom has silted up 1.31m due to deposition after the hydrodynamics weakened. An obvious feedback mechanism exited between the creek geomorphology and the hydrodynamics. The geomorphology factors, i.e., the slope of the creek bottom and the elevation, had impact on the hydrodynamics processes. For example, several velocity surges were observed in the tidal creek. These velocity surges can bring a mass of tidal water and sediment onto the saltmarsh surface, and strongly influence the evolution of the tidal creek and the upper saltmarsh. The grain size of surfacial sediments in the creek becomes finer from its mouth to the headwater; and the suspended sediment concentration at the mouth was higher.