A seismic-sedimentologic study was performed to map sediment-dispersal characteristics from the Shahejie-1 to Minghuazhen sequences in Qinan sag, Huanghua depression, China. Guided by third-order sequence-stratigraphic correlations from seismic and wireline-log data, we prepared stratal slices from a three-dimensional seismic volume to reveal high-resolution (10-m levels) sediment dispersal characteristics in a relative geologic-time domain. The strata from the Shahejie-1 to Minghuazhen sequences in Qinan sag can be divided into two second-order sequences and 10 third-order sequences. These sequences underwent a structural evolution history from stable rift faulting, to declining rift faulting, to depression with normal subsidence rate, to depression with accelerated subsidence rate. Many factors related to the structural evolution history controlled the sediment-dispersal characteristics, such as type of basin, dynamic mechanism, faulting activity, subsidence rate, presence of paleohighs, and others. Stratal slices depicted that the depositional evolution of these sequences was from braided-delta front, to delta front, to braided river, and finally to meandering river system.