The Cretaceous in northern Songliao Basin can be divided into three supersequence sets,eight supersequences and twentyeight sequences. Volcanic and coarse clastic successions formed during faulting stage contain three  supersequences and six sequences. Mediumcoarse grained clastics formed in the interim stage from faulting stage to depression stage contain one  supersequence and four sequences. During the depression stage the lithology is dominated by lacustrine and deltaic mediumfine grained clastics and can be divided into three supersequences and fifteen sequences. During the deposition of transgressive systems tract(TST)and highstand systems tract(HST)semideep and deep lacustrine dark mudstone were widely deposited. One supersequence and three sequences were identified during the shrinkage phase of lake basin when the lacustrine and deltaic mediumcoarse grained clastics were dominant.Supersequence set boundaries that were controlled by tectogenesis, include the top boundaries of Cretaceous bedrock, Yingcheng Formation and Nenjiang Formation, which correspond to regional unconformities formed by major tectonic phases of Yanshan Movement. Supersequence boundaries can be either supersequence set boundaries disconformities or erosional surfaces levels. At the supersequence boundaries, the depositional hiatus is quite long, so that channel downcutting, stratigraphic gap and exposure etc. widely exist. Supersequence boundaries are in accord with lithostratigraphic unit boundaries. Compared to supersequence boundaries, the depositional hiatus at sequence boundaries is shorter and sequence boundaries are not compatible with lithostratigraphic unit boundaries. Supersequence boundaries are characterized by truncation, onlap and toplap etc. on the seismic sections and sudden change of lithology and logging curve.