Previous studies (e.g., Satoh et al., 1995a) on inversion of quality factor for S waves, QS, of sediments using surface-to-borehole spectral ratios of seismograms, are mostly based on one-dimensional wave propagation of vertically incident SH waves. In this study a method is proposed for inverting frequency-dependent QS, S-wave velocity VS, P-wave velocity VP and incidence angle by considering ...