简要介绍地震与爆炸的震源物理性质及地震波激发机制特征。利用地震观测波形直达纵横波震相能量释放的差异，在时间域引进标志事件震源性质的参量a。132个台站记录的22个不同震源类型事件的计算结果表明，a值具有震源性质依附效应，展现出在事件识别领域的应用前景。

Characteristics of source physics and wave radiation mechanism of the earthquakes and explosions are briefly introduced. Based on the difference in observed direct Pand Swave energy, a discriminator a indicating source characteristics is defined in time domain of seismic records. The analyzed result of the 132 station records from 22 seismic events with different source types indicates that the a values does vary with source types, showing prospective applicability in seismic source discrimination.