Corresponding to different seismic activity between eastern China and western China, two schemes, which adopt different magnitude floor levels bounded as longitude 107 degrees eat, are chosen to calculate R-value. The first scheme is that M=5.5 in west China and M=5.0 in east China chosen as floor levels; the second scheme is that M=6.0 in west China and M=5.0 in east China are chosen as floor levels. Results indicate that the first scheme is more scientific, and average R-value of recent 13 years in China's continent is about 0.26. And then the predicted earthquake magnitude in seismic risk areas and the happened magnitude have also been taken into account, R-value of different magnitude levels have been calculated. Results show that earthquake predictions of M=6.0 in China are more successful.
Annual seismic risk area