Abstract: Based on the data of instrument observation, the test research results of the application of electric dipole depth-sounding in earthquake prediction, in the western part of China, have been summarized in this paper.
The observation results have indicated that the resistivities observed at each test site showed obviously abnormal change before earthquakes and the abnormal change amplitude in depth is larger than that in shallow part.The maximum amplitude is as much as 24%.As a result, the resistivity abnormal change observed in mid depth (2-6Km) by using electric dipole depth-sounding method is more obvious than that in shallow part (several hundred meters) measured by four-pole symmetric method observation, being used by many seismic stations at the present time.This depth coincides with that of the precursor advantageous layer proposed by Mr Guo Zengjian.