We estimate strong motion generation areas and strong motions during the 1923 Kanto earthquake by the forward modeling of the seismic intensity scale using the revised stochastic Green's function method. The nonlinear site effects on the seismic intensity scale are considered. The strong motion generation areas are located at almost the same position as large slip areas. Site amplification factors of spectral model and site coefficients of envelope model are interpolated by applying the Kriging method. Strong motions are spatially estimated using this method. The strong motion estimated at Hongo is consistent with the restored Imamura-type seismogram.