Abstract: Impedance amplitude measurement of six metamorphic kinds of tectonic coal was conducted under normal pressure and temperature. And then some phenomena were concluded as follows:amplitude spectrum of coal of different kinds respectively present different characteristics. In the test frequency range of 100 Hz~100 kHz, Z-f curves of coals all show monotone decrease. Through fitting of Z-M of tectonic coal, we can draw relevant formula, and use coal to validate, as the result, the edge band is obtained. In order to try to use coal and rock electrical response characteristic differences in frequency domain to reflect different conductive mechanisms and structure models of different coals and rocks, and then to use electricity exploration to prospect its compositions and structures, theoretical and experimental basis have been provided.