Abstract:Generally speaking,gealogical section has undergone structural deformation for several million years to several hundred million years.But the area,bed thickness and marker bed length remain unchanged;that is to say,the geological section keeps balanced before and after deformation.The balanced section platted according to the principle can serve as the standard by which we can verify whether the interpretation of geological structure is reasonable.We sketch out balanced section technique and its development.We also describe the forward and backward methods caf balaneed section technique,and their applications in geological interpretation.