Abstract: Based on the relationship of stratum uplifting(or sedimentation) and rising (or falling) of paleotemperature ,and the thermal history simulation of apatite fission track, beginning time of Cenozoic unconformity and sedimentation of Songliao Basin was confirmed here. Thermal history was also revealed accurately, that there are three episodes of alternative uplifting and subsidence: falling temperature with basin uplifting during 65.50-53.49 Ma, rising temperature with basin sedimentation during 53.49-40.31 Ma； second falling temperature with uplifting and denudation during 40.31-36.18 Ma, second rising temperature with successive sedimentation during 36.18-5.83 Ma； third falling temperature with uplifting and denudation during 5.83-1.79 Ma, and last sedimentation during 1.79-？Ma. Result shows that Yi’an Formation is the earlymid part of Eocene with the age of 53.49-40.31 Ma, Daan Formation belongs to the terminal of Eocene and Miocene from 36.18 Ma to 5.83 Ma，and Taikang Formation is a stratum of Pleistocene with the beginning age of 1.79 Ma.

Key words: Songliao Basin, Cenozoic, stratum age, thermal history