Abstract：The authors carefully analyse interdependence and variation of the factors inthe time-distance equation of P-SV wave,develop tnethod and softwares for derivingshear wave velocity(vs) from P-SV wave data,and describe their way for thc velocity spectrum interpretation.The shear wave velocity estirnated in this method hashigh accuracy and can be displayed in t0p,t0ps and t0s time coordinates.What is more,the shear wave velocity and cornpressional wave velocity can be nicely used to mark(or correlate) the reflection horizons in compressional wave and shear-wave sec-tions,and to estimate useful parameters for lithology exploration,such as Poissno'sratio,velocity ratio and so on.
