The article selects 11 significant and practical images at home and abroad with "symmetry and stuffing" method,and takes examples to explain according to different categories,and presents primary view on activity way of every group earthquake by stress field.

According to observation,there was some spatial and temporal precursory information in the seismic activity of M≥6.0 earthquakes at the both sides of the same latitude segment before Indonesia M8.9 earthquake,which occurred in Sumatra offing on Dec.26,2004,and the information can be tested through retrospection.Nevertheless,according to the records that recorded by Hongshan Seismostation,we can also get the prediction result of "active time interval".It is concluded that the seismic activity before strong earthquake,which is a kind "integer multidimensional activity",is basal information for earthquake prediction.

Due to the limitation of the data, theβ value of seismic zones have been determined by the historical seismic data at the present seismic hazard analysis. Because of lacking of historical documents, many moderate historical events were not recorded and the determined seismicity parameters have shown the uncertainty. It is difficult to describe the temporal inhomogeneous of the seismicity by the instrumental observation data with short time. This paper used the maximum likelihood method to joint two data with different precision and duration, which brings each superiority into play and overcomes each shortcoming. Therefore, it is possible for results to have more actual significance. The method for the estimation of the uncertainty and the sensitive analysis of these parameters have been shown. It might provide other way for estimation of the parameters in the seismic hazard analysis.