Based on the previous studies and field survey data, the authors carried out composite borehole profile studies at three sites and trenching at one site across the surface rupture zone of the Tangshan earthquake in a range of 31 km to the south of Tangshan City. The three borehole profiles are 4 km and 27.5 km apart from one another. Based on the research, the authors proved that the surface rupture zone of the 1976 earthquake extends to Xihe in Fengnan County and its total length reaches more than 47 km.The 1976 Tangshan earthquake is the newest activity of the Tangshan Fault that had multi-stage activities in the Late Quaternary. The displacement feature of the surface rupture zone is that the north branch is mainly of right-lateral strike-slip motion, and the vertical displacement of the surface is up on the west and down on the east, on the other hand, the vertical displacement on the south branch is up on the east and down on the west, accompanied by some right-lateral slip. In addition, in the light of the geological structure sections of this area, the authors discussed the relationship between seismogenic structure of Tangshan earthquake and geological structure, and proposed the suggestions about the next work.