The focal mechanism solutions of earthquakes and in-situ stress mea-surement results showed that there was a regional stress field in nearly radial pattern in Chinese mainland,and the radiation center was located in the eastern Qinghai-Xizang (Tibet)block.In this paper we defined the approximate radia-tion center (35°N,100°E)in Chinese mainland as the dynamic source point and then calculated the distance between the dynamic source point and the locationof 34 earthquakes with MS ≥6 .0 since the year 1 900 in eastern part of Chinesemainland (30°N—44°N, 1 04°E—1 2 5°E ) so as to analyze the relationshipbetween the distance and earthquake occurrence time.The results showed that aseries of MS ≥ 6 .0 earthquakes occurred in North China block after an earthquakewith MS ≥7 .0 occurred in North-South Seismic Belt in the 20th century,and they generally migrated eastward from North-South Seismic Belt with time.This also suggested that the earthquakes occurred in North China block shouldbe mainly controlled by the influence of the Qinghai-Xizang (Tibet)block’ssqueezing to the eastern Chinese mainland under the action of Indian Plate,causing the MS ≥6 .0 earthquakes eastward migrating in the North China block.There were four distinct groups of migrations with velocity about 80 km/a.Theinterval between the first MS ≥ 6 .0 earthquake in North China block and thelatest MS ≥7 .0 earthquake in North-South Seismic Belt was about 1 month to1 1 .8 years,and 60% of the MS ≥6 .0 earthquakes were located in the area closeto (3 9°N±1 .5°).Therefore it could be inferred that the MS ≥6 .0 earthquakesprobably occur in North China block in recent years after the Wenchuan MS 8.0earthquake in 2008 and Lushan MS 7 .0 earthquake in 20 1 3 .Accordingly,weshould focus on the j unction areas of Shanxi,Hebei,Inner Mongolia,and thecircum-Bohai and their surrounding areas.%地震震源机制解和地应力实测结果表明，我国大陆地区存在近似于辐射状的区域应力场，其辐射中心位于青藏地块东部．本文首先定义我国大陆应力场近似辐射中心（35°N、100°E）为动力源点，在此基础上计算了1900年以来我国大陆东部地区（30°N—44°N、104°E—125°E）所发生的34次 MS ≥6．0地震震中到动力源点的距离与地震发生时间的关系．结果表明，20世纪南北地震带中北段发生 MS ≥7．0地震后，华北地块陆续发生了一系列MS ≥6．0地震，且有随时间从南北地震带附近大体向东迁移的规律．据此说明，华北地块的地震主要受控于印度板块作用下青藏地块向我国大陆东部挤压的影响，在其作用下产生了华北地块 MS ≥6．0地震的系列东向迁移活动．总体来看有4组明显的地震迁移活动，每组地震“序列”的迁移视速度约为80 km／a．华北地块首发 MS ≥6．0地震距南北地震带中北段最近一次 MS ≥7．0地震的时间间隔约为1个月至11．8年，且60％的 MS ≥6．0地震发震地点在（39°N±1．5°）区域内．据此推测，2008年汶川 MS 8．0和2013年芦山 MS 7．0地震后，华北地块近年存在发生 MS ≥6．0地震的可能，晋冀蒙交界和环渤海及其附近地区值得重点关注．
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