Abstract: There are two methods for detecting the earthquake precursors： the first one is to de-·tect the energy leakage in the process of earthquake preparation; the second one does not rely on detecting such energy leakage. To obtain the necessary precursory information, the first method should be improved, and we also pay more attention to develop the technique of the second method. According to the fact that scientists have built many seismic networks monitoring high-frequency crustal movement, and GPS networks monitoring low-frequency crustal movement, and only a few observational stations for intermediate-frequency crustal movement. We believe that the intermediate-frequency band is very important for earthquake prediction. We need to build the concentrated and fixed observational networks for monitoring the intermediate-frequency crustal movement. In the meantime ,the observational precision and the signal-noise ratio of intermediate-frequency instrument needs to be enhanced.

Key words: Earthquake precursor, Observational frequency band, Observational precision, Concentrated and fixed network for crustal deformation observation