Abstract: Sediment problem is one of the key factors which affect the dispatching operation and life of the Three Gorges Project (TGP). Many approaches were employed to research the sediment problems of the TGP during its demonstration, planning, design, construction and operation, and many important results were obtained. It was confirmed that the previous sediment research results are reasonable and reliable by analyzing the field data of the actual testing operation of TGP. The 10-year operation of TGP shows that the basic situation of sediment problems is good, and the local problems were or are in control through proper treatment. However, these sediment problems can probably accumulate, develop and transform with time, so they should be paid continuous attention. The influence of the TGP operation on the relationship between rivers and lakes was also analyzed in this paper. It was pointed out that intense and large-scale erosion happens in the downstream channel of the dam since TGP operation, and the water levels at the outlets of Dongting Lake and Poyang Lake have decreased, which has some influence on the water and sediment diversions and results in sharp contradiction of water resource supply and demand in dry season for both lakes. It is effective and feasible to solve the existing problems through constructing sluices and other measures in the Dongting Lake and the Poyang Lake.