Previous researches on relative sea (lake)-level curve in Pearl River Mouth Basin mainly focused on the Neogene marine basins. Due to data limitations, there are few in-depth studies of the lake level changes of the Paleogene continental basin. Wenchang formation in Enping sag is an important source and reservoir segment, but relative lake-level curve can only be studied according to the seismic data because of no drilling drilled through Wenchang formation. Based on 3D seismic data, the relative lake-level curve of Wenchang period were plotted quantitatively by means of Wheeler transform，then it was compared with the curve qualitatively constructed by traditional onlap reflection. The results show that both curves consistent with each other in the overall trend, but recognition accuracy are different. Quantitative relative lake-level curve has the following advantages: ①High resolution, not only reflects the overall trend of lake level, but also effectively reflects the small magnitude of lake level fluctuations, providing conditions to identify high-level sequence stratigraphic unit;②Objectivity, qualitative relative lake-level curve constructed by onlap reflection are mainly based on human subjectivity with multiple interpretations, while quantitative curve by means of Wheeler transform is more objectivity without human impact and effectively reducing multiple interpretations; ③High efficiency, quantitative automatic sequence stratigraphy tracking effectively reduces the workload of human interpretation and greatly improves work efficiency. Based on the constructed relative lake-level curve, Wenchang formation could be divided into two rifting cycles and further subdivided into seven three-order sequences.