Abstract: The basic principle and process of loggingwide- band constrained inversion are presented in thispaper. The key to wave impedance inversion lies in seismicgeologic horizon demarcation of synthetic seismogram andvelocity modeling. In lithologic interpretation of inversionresu1ts,both variations in color code and wave form andgeological factors should be considered so as to eliminatethe influence of special lithology and uniform standardsfor predicting sand body boundary should be established.