In the continental margin of the northeastern South China Sea, the sea level fluctuations since the Last Glacial Maximum have profoundly impacted the sedimentary environment. Our sub-bottom profiler data show a sedimentation process change from deposition to erosion during the Last Glacial Maximum. After the widespread erosion, the sedimentation process returned depositional throughout the Holocene, probably due to the rise of the sea level. This sedimentary process results in a widespread sedimentary unconformity in the continental slope, providing a benchmark for the end of the Last Glacial Maximum. Analyzing the sediment cores, we affirm that the change in current intensity is the primary factor controlling the sedimentary environments. The current intensities strengthened during the eustatic lowstand and weakened during the highstand periods, leading to alternating erosional and depositional processes. The widespread distribution of the erosive surface represents a regional-scale change in the sedimentary environment instead of a local event.