Abstract: It is found that the coseismic effect phenomena of precursory observations existed generally around the occurrence of strong earthquakes with magnitudes equal to or over 7. 0 and the area covered is very large. Of these effects, some are related with earthquauakes, the others with some potential strong events. Generally speaking, the study of these coseismic effects of precursory observations can benefit us with following three advantages:
1. The obvious area of the coseismic effect may be the site for the coming strong earthquake.
2. The coseismic anomalies are directly related with earthquakes. They could provide us with reliable evidence for the future event prediction.
3. The appearance of the coseismic anomalies has an apparatus synchronism, so the concentration of the coseismic anomalies in a large area may show us the valuable imminent message for strong earthquake prediction.