Abstract: Except for earthquakes occurred in Taiwan and Himalayan region as well as the deep-seated swarm earthquakes in Northeast China, all of earthquakes in China are attributed to intraplate earthquake. Then, what are their origins? In the present paper, the emphasis is placed on the crustal stress field related closely with the earthquakes in recent and the youngest geological time in China. Data from geology, seismology, and geodesy demonstrate that in North China there is a significant change of stress field in middle Tertiary, while in the rest areas of China the crustal stress field remains principally unchanged since middle Mesozoic. It is suggested that the pattern and variation of the crustal stress field in China are caused by the action of plates surrounding the mainland of China.However, intraplate earthquakes in China are not only connected with the plate tectonics, they also depend upon the remarkable features of fault block tectonics in the mainland of China. It is noted that some deep geological features found in the seismic areas are a very important clue for studying the origins of intraplate earthquake.

摘要： 根据地质学、地震学和地形测量的资料认为:华北地区第三纪中期地壳应力场有一次重大变化,而中国其它地区自中生代中期以来地壳应力场基本未变。我国地壳应力场的这种布局及其变化看来是起因于中国大陆周围的板块活动。 讨论了我国板内地震和断块构造的关系。指出了值得加强研究的地震区域的某些深部地质现象。