Abstract: Passive water storage tank of AP1000 nuclear power plant (NPP) ensures water supply for 72 hours. Water sloshing in water storage tanks can have a significant effect on the dynamic response of NPP under seismic loads. In this paper, based on the Arbitrary Lagrangian Eulerian algorithm, coupled detailed finite element models of AP1000 shield buildings with four cases of water levels and three kinds of air intakes were established to analyze the dynamic response when the structure was subjected to NPP artificial earthquakes that match the RG1.60 spectrum. The interaction rule of the accelerations at different water levels, locations of air intakes and dynamic response are parametrically analyzed. The optimal water level and air intakes are explored. The analysis results show that, on the premise that the water supply satisfies the NPP operating condition, the minimum dynamic response of AP1000 NPP can be achieved for the water level 4 and air intake C.