Current cross section balancing technique is not suitable for the paleostructure reconstruction of most of extensive basins since they underwent 3-D deformation.The reconstruction of the 3-D deformed paleostructures should be considered as the superimposition of 2-D deformation.The faults in the 3-D deformed basins could be divided into isolated faults and fault complex

and they should be treated separately in reconstruction.As an example

the 3-D paleostructure of the boundary between Middle Eogene and Cretaceous in Tangyuan Depression is reconstructed and described in this paper.