Abstract: In this paper, the field investigation result on macrointensity of the Tangshan M5.1 and M5.3 earthquakes on May 29 and 30,1991 is presented first, the seismic hazard characteristics indicate that the future seismic activity could not produce great influence on the production and daily life in Tangshan re-gion, and then, combining relative microdata, the relationship bitween these two earthquakes and the Tangshan earthquake sequence in fracture is analyzed, the analysis result indicates that these two earth-quakes are repeated earthquakes with similar, fracture mechanism, occurring in the NE-NE extended fracture plane of the Tangshan M7.8 earthquake, belonging to a late strong aftershock and having no re-lation to the seismic activity in North China area.