Abstract: A three-dimensional hydrodynamic model coupled with a Lagrangian particle tracking model was applied at the Xiyang, Chenjiawucao, Kushuiyang, and Huangshayang tidal channels in the radial sand ridges area of the South Yellow Sea, in order to investigate the flow and mass exchange characteristics between different channels. Results showed that net displacements of surface particles in the flood tide were larger than that in the ebb tide. During the neap tides, the particles in both the surface and bottom of four channels were limited in respective channels characterized by similar reciprocating trajectories. During the spring tides, the particles moved along reciprocating straight lines or in a clockwise spiral. The trajectories of particles changed across different channels, layers and at different releasing time. The particle movement range of the surface layer was larger than that at the bottom layer. The hydrodynamic characteristics of the radial sand ridges are responsible for the significant differences of transport characteristics in different channels. The Xiyang channel is controlled by the reciprocating flow while other regions are dominated by the swirl flow of the different degree. The vertical circulation and water exchange in tidal channels were more obvious in spring tides compared to those in neap tides. The crosswise transport of the particle depended on the relative flow velocity of the vertical circulation. The special geomorphology also played an important role. Most particles of the vertex of sand ridges were shoreward, only a few were along the south and north shore, indicating the shoreward tendency of the water movement and mass transport. The outcomes of this study may provide theoretical support for environment management regarding radial sand ridges.