Based on the sequence stratigraphy theory, this study analyzed the main structural sedimentary cycles and key sequence boundary features of Paleogene in the beach area in Liaohe depression, and four secondary-order sequences and eleven third-order sequences were defined. The results reveal that the sequence development features of Paleogene in the study area are mainly controlled by tectonic movement, tectonic intensity and sedimentation cycles. The secondary-order sequence boundary can be considered as the transition interface of the structural configuration and sedimentary environment, controlling the sedimentary system and types of sedimentary facies. The third-order sequence boundary can be considered as the transition interface of the sequence superposition pattern and sedimentary environment, controlling the features and evolution of system tract within the sequence.