The characters of outerbar and inner}tre}nn reach in the Yangtze river estuary are presented by analysis of streambed evolu-tion. Based on the value and distribution of flow velocity in construction stage by 2D hydrodynamic mode上the failure mechanism of beach and bank protection works is stud-ied from hydrrodynamic, construction and streambed evolution. At last, the stratag-ies of beach protection and accretion pro-motion in constrution and plan layout of groin and longitudinal dam are presented.