Abstract: This paper describe the spectral seismogram(seismic topography) had developed the concept of spectral magnitude which was introduced by S.J. Duda, the calibration functions for broad-band digital recordings of P-waves. The method of spectral seismograms, which was developed by Stefan Fasthoff and Duda to analyse Strong shock in and near China in recent years. This method had been used to classify seismic sequence types by its color feature: red-quake with lower frequency in P or S-wave group, and blue-quake which contained with more larger frequency elements in P or S-wave group by the filter of digital seismic records.