In order to study the formation mechanism and distribution of the sand bodies developed in Qing 1 and Qing 2 members of Upper Cretaceous in Songliao Basin, with the application of the principle of high resolution sequence stratigraphy, sequence boundary marks were determined and a kind of sequence boundaries of shift surface of deposition were identified according to core, drilling/logging and seismic data. According to the research of sequence boundaries, one long-term base level cycle and three medium-term base level cycles were recognized in the target formations. Based on stacking modes of medium-term to long-term base-level cycles, the stratum mode of medium-term base level cycles is symmetry, but the stratum mode of long-term base level cycles is mainly composed of rising half cycle which composed rising asymmetry cycle configuration. Sedimentary facies and the distribution of sand bodies are mainly controlled by the change of base level. The delta front sand bodies are distributed in the rising and falling stage of medium-term base level cycles, and the turbidity sand bodies are only distributed in the rising stage of medium-term base level cycles. This understanding will be favorable for oil and gas exploration in the study area.