A succession of high-resolution large scale bedform movements composed of very fine sand are shown by the high resolution survey records. They are detected by Thermal Depth Recorder, Sonar Side-scan, Endeco Current Meter along two profiles, and Optical Suspended Concentration Meter, Acoustic Suspended Concentration Profiler and D.GPS at one fixed station in the Changjiang Estuary during the last period of 1998 disastrous flood. The scale of bedform and their movement are several times of those detected during the dry season. These results can provide the practical data about the tremendous quantities of bedload transport, which is the mainly ambiguousy long-standing problem resulting in serious shallowing in docks and navigation channels, especially for the present construction of Deep Water Channel in the Changjiang Estuary.