Abstract: Using the earthquake data occurred in China's Mainl and, the analytical results indi-cate that the seismicity of M≥ 7$\frac{2}{2}$ earthquakes since 1900 shows grouping and regionalization feature. The authors consider that Kunlun Mountains' strong earthquake with M_S 8. 1 marks the start of the fifth earthquake activity group. The rang e of radius 500~ 1000km from the epicenter of the M8. 1 event is the main earthquake activity site in the coming six years. The study result indicates that it is possible that the earthquake with M≥ 7. 0 takes place in China's Mainl and in three years.

Key words: China's Mainl and, Seismicity cycle, Earthquake activity group, Kunlun Moun-tain earthquake with M_S 8. 1