Abstract: Cenozoic East Sag of Liaohe Basin consists of double structure and is a fault-depression basin with extending and strike-slipping.There is different tectonic effects in different periods that is to say extension predominated in the early and strike-slip in the late through the research about the geometric,kinematics and dynamics of the basin.Fault depression is composed of different-type half-grabens. Structural style evolution sequence is from non-tilting half-graben to tilting half-graben,structure styles in the early of fault depression,rollover half-graben and half-graben and ramp-sag are in the middle,and half graben and ramp-sag and strike-slipping half-graben in the late.Depression (From N g to now) is the style in the period of Cenozoic rift basin shrinking.The research of different period structure style reproduces actually the history of structure styles evolution.At the same time,it is a precondition of petroleum system about oil pool formation processing.