Based on the present documents, this article reviews some progress made through studying the influence by vegetables in the salt mash on hydrodynamics, sediment transport, sedimentation and geography. The progress includes: (1) the loss of wave energy in salt mash per unit distance is several times to dozens of times that in adjacent tidal flat; besides, all the wave energy may disappear when the wave is transmitted 20~30 meters into Spartina alterniflora salt marsh. (2) the vegetables in salt mash can cause the tidal flow to decrease one order of magnitude; when the plant canopy is drowned, there is a reversal of flow velocity gradient over the canopy. (3) when the plant canopy is drowned, the turbulence intensity along depth in canopy tends to be uniformly distributed and obviously lower than that above the plant canopy; the turbulence intensity in Spartina alterniflora salt mash is lower one to two orders of magnitude than that of adjacent tidal flat. (4) the vegetation affects the sediment transport through two mechanisms, one of which is to reduce turbulence intensity of water, which promotes the sedimentation of suspend sediment and stop the surface sediments to re-suspension; the other one is the direct trap sediments by stem and leave of vegetation. The two mechanisms can reduce the concentration of suspend sediment in salt mash to half or even less as much as that in adjacent tidal flat. (5) the accretion promotion of vegetation to fine sediments leads to refining of bed sediments in salt mash. (6) the vertical sedimentation rate in salt mash is seven to eight times that in adjacent tidal flat; the difficult growth of micro-geomorphology such as ripple marks and corrosion craters in salt mash tends to form evenness in salt marsh; Compared to frequent alternation of erosion and accretion in tidal flat, the salt mash usually accretes more than erosion, which forms relatively high stability in bed . (7) the influence of the vegetation on the above-mentioned sedimentation dynamics is closely related with such ecological parameters as height, density and coverage. Therefore, different plant species influence the process of sedimentation dynamics differently. Based on the above analysis, the authors presents the outlook of several aspects that need further study in the future.