Abstract: In this paper, characteristics of seismic activity in juncture area of Shanxi, Hebei and Inner Mongolia are analyzed, the results show that since 1929, earthquakes with magnitude of M_S ≥ 6.0 in the area are mainly in the Hetao seismic belt and Zhangjiakou-Bohai seismic belt, at latitude 40 degrees and the surrounding area forms a dominant distribution area;Since 1970, the medium earthquakes are mainly distributed in a triangle region formed by Helinge'er of Inner Mongolia, Datong of Shanxi and Zhangbei of Hebei. A seismic quiescence of moderate earthquake lasted 1304 days since September 2005 in the study area is broken by Shanxi Yuanping 4.2 earthquake;Daihai fault has sustained calm since November 1997.The moderate earthquake quiescence in study area and Daihai fault has obvious implications to medium earthquake of the research area and Hetao seismic belt, as a significant earthquake signs, agreat deal evidences show that Shanxi, Hebei and Inner Mongolia triangle area as well as huhetaote-baotou fault are favourable zone of earthquake, the seismic intensity may be M_S6.0.