Abstract: The systematic summarization is made for the relation between tidal force and significant shock and its application in the short-term and impending earthquake prediction, and our proposed prediction method based on characteristics of significant shocks is improved in this study. The method is named CH method for short. In all 21 short-term and impending predictions from Jan. of 1997 to May of 2003 using CH method, 12 earthquake cased are of the better and a certain extent prediction, accounting for 57%. It indicates that our proposed short-term and impending earthquake prediction method i.e. CH method shows better effect in earthquake prediction.

Key words: Tidal force, Significant shock, Earthquake prediction, Critical state