According to abundant experimental results, this paper has described and summed up properties of electromagnetic radiation produced during the rupture of rocks or ores under pressure. In the process of rupture, ores that contain quartz and metallic sulfides can produce electromagnetic radiation signal of unique wave form with frequency spectra 500 kHz～1 MHz; nevertheless, signal characteristics at higher or lower frequency spectra are similar to those of other rock types. Therefore, the application of seismic source electromagnetic radiation method to ore prospecting is based on certain physical prerequisties and also suffers from the interference signal caused by barren bodies.