Abstract: Seismic wave is affected by many factors during the propagation,which makes the phase change.In addition,data processing also distorts the phase of seismic record to varying degree and changes the waveform of seismic wave.Typical models were established based on the main factors which impact the phase of seismic wave.By forward modeling,the impact of some factors on the phase of seismic wave were analyzed and tested,including viscoelastic medium formation thickness,rhythm layer,and progressive layers and bending interface.Several conclusions were obtained from the forward modeling:①when the Q value is small,the phase becomes more delayed as Q decreases;②when the thickness of the thin layer is bigger than 1/4 wavelength,the phase becomes more delayed as the thickness increases;③the phase becomes more delayed as the thickness of the sequence in rhythm and progressive layer increases;④compared with horizontal interface,the phase of anticline interface is slightly advanced while the phase of the syncline interface is slightly delayed,and the phase alternation amplitude of the syncline interface is smaller than that of the anticline interface.