Abstract: Numerous nonlinear time history analyses of single-degree-of-freedom bilinear system are carried out by the use of large numbers of seismic waves. These waves have the same response spectrum and the similar envelope in time-domain. The seismic response features of structures with bilinear seismic isolation devices are discussed. The influences of parameters on seismic response of seismic isolated structures are studied. These parameters are the initial yielding displacement and the ratio of the inelastic stiffness to the elastic stiffness of bilinear seismic isolation devices. The present results may have some reference value to the designing of structures with bilinear seismic isolation devices.