The features of seismicity in the north area of Qinghai-Tibet Plateau are obtained:
(1) The active period of earthquake is about 230-250 years long, the tranquil period is about 130 to 150 years long.
(2) The seismicity has a relation to the seismic activity in the south area and the south edge of the Himalayas. After stronger earthquakes occurred in the south area of the Himalayas and the north area of Burma, there would be stronger earthquakes to occur in these areas with probability 87.5% and 66.7%, respectively.
(3) The earthquakes with M≥7 took place alternatively in several seismic zones. The first two earthquakes with M=6 would point out the furture location of next earthquake with M≥7.
(4) The medium earthquakes were not in active before the earthquakes whth M≥8, but were active before the earthquakes with M≥7. Generally, the medium earthquakes happen in north and west parts of Qinghai and southeast part of Gansu or in the edge of Gansu and Sichuan before the earthquakes with magnitude about 7.
According to above results, there may be an earthquake with M≥7 in the north area of Qinghai-Tibet Plateau in coming 10 years.