Abstract: The difference of earthquake precursors reflected on different survey line at earth resistivity stations now operating in China is studied by uing the normalized monthly rate method and theoretically explained by means of earth resistivity anisotropy mechanism. Meanwhile, the application of earth resistivity multi-orientation observation in earthquake prediction and principal stress state reversion is introduced. The following results are gained: First, the earth resistivity multi-orientation observation now operating in China can indeed detect the resistivity variations which have connection with earthquake preparation, the multi-orientation observation is the best moment setting mode to catch the preursor information, which have good earthquake-reflecting ability both for near-field and far-field earthquakes. Second, the stress state and dynamic process in epicenter and its vicinal region during the middle-short term to short-impending term of earthquake preparation process can be realized by using earth resistivity multi-orientation observation data.

Key words: Earthquake precursor, Earth resistivity, Anisotropy, Multi-orientation observation, Earthquake-reflecting ability