Abstract：At present，people have been successfully studying how seismic wave origi- nates，propagates and attenuates in an isotropic and full elastic multilayer half space. Little research on seismic wave field in porous multilayer medium has been done however. Full solution of seismic wave field in two-phase medium is then de- rived from Biot's wave equation system in two-phase medium,thus obtaining trans- mission matrix in the two-phase medium. A new data processing method is given which is applicable to the new medium where two-phase layer is replaced by equiva- lent homogeneous solid layer. By taking as seismic source the exploding point force，vertically concentrated force or horizontally concentrated force at shallow underground，we calculate the displacement field of free surface of half space consisting of two-phase medium,andanalyse the influenceq chie:‘，reservoir parameters，horizon，bed thickness and so on.
