北京是我国政治、经济和文化中心，中等有感地震会引起极大的社会影响。北京地区面积小、地震较少，缺少有效的中等地震短期预测指标。通过对1970年以来首都圈中部地区的小震活动图像全时空扫描与研究，认为该地区的近南北向异常小震条带可以作为北京及邻近地区中等地震前短期预测指标。

Beijing region is the center of political，economic and cultural in china，the medium earthquake that is sensible may cause great social impact. As the small area of the region with few earthquakes, and other reasons, it lacks more effective shortterm prediction index. Through the whole spacetime scan analysis of the small earthquakes activity image based on the central the capital area since 1970, it is found that nearly southnorth abnormal belt of the small earthquake is a shortterm prediction index before the moderate earthquake in Beijing and adjacent areas.