Based on an analysis of characteristics of sediment transportation and flow field in sea areas of

Hanjiang estuary by using the multi-temporal landsat image, this paper deals with the hydrodynamic condition of

Hanjiang estuary and its impacts on sediment transportation. Some conclusions have been reached: ①Sediment

concentration in the Hanjiang estuary is low; ②In the estuary, the tidal current runs from southwest to

northeast; ③ Outside of the estuary, the flow  from the Hanjiang river is affected by the southwest current, and

the suspended sediments are transported along the boundary.