Abstract: Many dams accidents result from its abutment stabilizing failure caused by the high groundwater level. The seepage of the bypass dam is one of the factors to bring about the rise of the abutment groundwater level. As to the decrease the ground-water level of the dam abutment,the seepage proofing curtain of the dam base extends deep into the banks of a reservoir. At the same time,the behavior of the seepage proofing curtain changes with the time. To evaluate the behavior of the seepage proofing curtain and groundwater level of the dam abutment,we analyze the observation data of water table of dam abutment and the influential factor of the groundwater,such as water level of a reservoir,rainfall,temperature,ageing effect and the coordinates of point location.And the expressions of the effect factors of abutment groundwater were developed.Then,based on the observation,the spatial temporal distribution model for the groundwater elevation of the dam abutment is established by the least square method. The abnormal points that have high groundwater elevation are located by comparing the standard deviat ion of the fitting model with the points And the seepage behavior of whole dam abutment is discussed and the weak seepage part of the abutment is located and monitored.