In this paper, according to the historical documents, the perceptible area, destructive area, meizoseismal area and the distribution of aftersho- okes of the strong earthquake (7.5) in Northern Shanxi Province on May 21, 512, as well as the seismic activity of Northern Shanxi Province bef- ore the earthquake are studied. The epicenter of the strong earthquake may ue located in 38°50′N and 112°50′E in Dai County. The direction of the causative fault is NNE.