Based on the overall study and comparative analysis

the theory of oilfield structural analysis was used to understand the structure features and dynamic mechanism of basin formation during the deposition of the Kongdian and Shahejie formations in Western Bohai Sea

so as to reveal the distribution of source rocks in the Kongdian and Shahejie formations and guide play evaluation and exploration target selection. Basin architecture was controlled by basement structure

and tectonic deformation was different in the east and west due to the difference of crystalline basement types. In addition

the tectonic deformation was influenced by two pre-existing NE-NNE-trending and NW-NWW-trending conjugate basement faults

resulting in the E-W zonation and N-S segmentation in the west part while E-W segmentation and N-S zonation in the east part. Structure features in different deposition periods of Kongdian formation and Shahejie formation vary largely

showing an evolutionary sequence of downwarp-fault depression-fault depression and fault-downwarp depression（ depression）. And the structural deformation during despotism the Kongdian and Shahejie formations in western Bohai Sea was controlled by vertical extensional stress field induced by mantle diapir and uplift. Tectonic deformation in the east part was mainly controlled by the near SN extensional stress field

while that in the west part was controlled by the superimposed NW-SE and near SN extensional stress fields.