Abstract: The integrated definite element model of vertical circulation pump assembles in AP1000 was built. The static analysis and response spectrum analysis were used for normal design condition and design earthquake condition respectively, and the integrality and operability of pump were evaluated through strength and displacement analysis. The results demonstrate that the 1st lateral natural frequency of the pump is 14.4 Hz, and the first 4 vibration mode shapes consist of an effective mass ratio of 0.94 in the model under a horizontal excitation load. At the design seismic load condition, the max combination stress of pump case as the main pressure-bearing container is 203 MPa, the max displacement in impeller case is 1.5 mm, the max combination stress of motor assemble is 1.7 MPa, and the max displacement of motor assemble is 0.8 mm, all these results are allowable in design. The analysis results demonstrate that the integrality and operability demands of pump are met in this design.