Multiple regression analyses for vertical peak ground motions (peak ground acceleration, peak ground velocity and peak ground displacement) and absolute acceleration response spectra with damping ratio of 5% of critical are presented. Employed were 119 sets of vertical strong motion acceleration records obtained at 53 free field sites in Japan. Empirical formulae of these characteristics in terms of earthquake magnitude and epicentral distance are proposed for three subsoil conditions. Peak ground motions and absolute acceleration response spectra of vertical components were compared with those of horizontal components, and characteristics of vertical components were discussed in comparison with the characteristics of horizontal components.