In order to study the interaction law between underground and surface structure system of different stiffness

three kinds of surface structures with different stiffness are constructed.The three structures are characterized by their first natural frequency based on whether it is less than

greater than or equal to that of the soil layer.The underground structure is a typical subway station with a three-layer and three-span frame.The Davidenkov model is employed to consider nonlinear characteristics of soil.Seismic wave type and amplitude are also considered in the paper.The calculation and analysis results show that site response is amplified because of the existence of underground structure

while the influence of the upper structure on site response depends on system frequency.Meanwhile

single upper structure has little effect on seismic response of underground structure

while the underground structure greatly amplifies the seismic response of the upper structure

and the amplification degree also depends on the system frequency.