Abstract: Inflow Control Devices(ICD) represents a new well completion technology for controlling bottom water which provides uniformity of the inflow profile by restricting high specific inflow segments while increasing inflow from low productivity segments. This paper studys with numerical simulation the effects of the proportion of high permeability zone, permeability grading, the length of control section and the flow rate of control section on the water breakthrough performace of a reservoir with bottom water using ICD,and determines the optimum placement of inflow control device, the flow resistance rating and the length of control section.The results show that the smaller the proportion of high permeability zone is and the larger permeability grading is,the better the water breakthrough performace of a reservoir with bottom water is in heterogeneous reservoirs,and ICD mounting location, length and limit flow rate have an importantment of water breakthrough performace of a reservoir with bottom water. In order to make the water control and oil increment effect maximization, ICD should be installed in horizontal well section of high permeable zone, and the length must be equal to or slightly higher than the high permeable zone length. The flow rate in the high specific inflow segments shold be as close as possible to the average flow rate in all sections.