Based on the aqueduct beam element dynamic model with fluid-structure coupling,the seismic response of signal pier aqueduct under earthquake is calculated.In this model,the transverse、vertical、longitudinal deformation and restraint twist deformation,as well as the fluid-structure coupling between aqueduct and water body are all taken into consideration.It is shown the correctness of the solution.The model is practicable and the calculation results provide consults to the anti-seismic design of aqueduct.