Abstract: Based on the characters of short duration and abrupt change of blasting seismic signals, and the monitoring data from a blasting engineering, energy distribution of blasting seismic signals are analyzed by using the time-frequency localization of wavelet. The law of energy change of blast seismic signals during the spread is studied, the energy distribution of blasting seismic signals in different frequency bands is obtained by means of the wavelet packet analysis, which has high resolvability and localization. Relations between characteristic frequency at different frequency bands of blasting seismic signals and natural frequency of controlled structures confirm the effect of blasting seism on the structures. An engineering example illustrates that the proposed method is more effective than a single intensity factor as the safety judging standard for blasting seism.