Abstract: A large number of river harnessing projects were carried out in the North Branch of the Yangtze River from 1991 to 2010 and the nature dynamic sedimentation environment was impacted by the human activities. In order to study the characteristics of sediments in the North Branch under the new flow and sediment conditions, this paper analyzes the sediment samples taken in a large scope during typical wet year of 2012 and typical dry year of 2013. The results show: (1) The mean median diameter of the sediments in the North Branch is 0.055 mm, belonging to coarse particles. The dominant sediments are clayey silt and sand, and the sand is mainly distributed in the upstream reach of Lingdian port, while the clayey silt is mainly distributed in the reach from Xincunsha to Lianxinggang. (2) In the longitudinal direction, from Chongtou to Lianxing port, the overall decrease trend of mean median diameter of the sediments was observed, and the difference in sediment characteristics was significant. Taking Lingdian port as the boundary, the median diameter of the upper section was about 2.5 times that of the lower section. In the transverse aspect, the grain characteristics are mainly coarser in the channel and finer on beach. (3) In wet years, the sediment particle size is larger than that in dry years, especially in the upper reach of Lingdian port where the sediment comes from the upstream river rather than from the sea.