On the basis of 1∶1000000 remote sensing interpretation and local comprehensive interpretation, it is thought that the northeast part of Deerbugan deep fault might branch into two diverging faults near Alongshan of Inner Mongolia. These two diverging faults have identical characteristics, and extend to Russia in NEand NNE-NE direction respectively. They are linked at an acute angle with the south and middle part of Deerbugan fault near Alongshan, forming a prominent Y-type faulted structure framework.