The navigation condition of the fluctuating backwater zone of the Three Gorges Reservoir should improve its level from 3.5 m to 4.5 m in order to meet the development requirement of the Yangtze River economic belt,and the bed load transport at the reservoir head is the problem must be dealt with.Based on the 2D hydrodynamic-sediment transport numerical model for the Three Gorges Reservoir,the deposition and scouring process of the river reach from Chongqing to Fuling was simulated according to the water discharge and water level record from 2009 to 2016.The results were in good agreement with the field measurements for the sedimentation distribution and gravel bed load transport rate at from Chongqing to Fuling,illustrating the capability of the two-dimensional model to predict the bed load transport process in the Three Gorges Reservoir.The 2D numerical model was then applied to predict the change trend of the river reach in the next 30 years and analyze the distribution of the sedimentation,the density of the gravel bedload transport and its characteristics to investigate the influence of the gravel bed load behavior on the navigation condition in the key river reach.The results can provide technological support for the 4.5 m level waterway regulation in the fluctuating backwater zone in the Three Gorges Reservoir.