Abstract: The region surrounded by seismic intensity Ⅵ isoseismal line denotes the area that the earthquake affected. Seismic intensity Ⅵ isoseismal maps of 102 earthquakes in China since 1990 are analyzed in this paper. China continent is divided into west and east areas by the line of longitude 105°E and we'll research into the relation between the major axis and minor axis of the isoseismal maps and that between the major axis and magnitude in the two areas mentioned above. After this, we can get the experiential coefficient. Besides, the coherence of the direction between the intensity Ⅵ major axis and the nearest fault will be discussed. To a certain extent, this research is useful for fast estimation of the parameters(major axis, minor axis, direction of major axis) of the seismic intensity Ⅵ region in the earthquake emergency and response.

Key words: Seismic intensity, Magnitude, Isoseismal line, Fault direction