Great earthquakes M ≥ 8 in China are basically distributed in 5 seismic zones and bands:southern Qinghai Tibet Pleateau and Yunnan seismic arc zone, NE striking seismic band in northeastern Xinjiang area, 35° N line and South-North seismic band, Northern China strong seismic zone, and Taiwan seismic zone. Very often, the great earthquakes occur in pairs, or with predominant period. Different dynamical sources may exist for the great earthquakes in different seismic zones and bands. 3~10 years after the occurrence of an M ≥ 8 earthquake in Xinjiang area or Taiwan area, a dense seismic activity with magnitude 6. 5 may appear in north part of Northern China area, and 7~15 years after the event, Jianghuai seismic zone may enter a seismic active period with the magnitude 6 earthquake as the mark. The great M ≥ 8 earthquakes in Northern China have obvious seismicity reducting effect on the two sub-zones of Northern China zone.