Abstract: This paper recovered the paleotopography of late Sanduo, establishes the burial history and thermal history by using the highest paleotemperature method of vitrinite reflectance and the mapping method of mudstone acoustic time difference to estimate the eroded thickness on hanging wall and footwall in Wubao?Bozhen fault zone in Gaoyou sag. The results show that the eroded thickness on footwall is 1400~1 700 m, and that on hanging wall is 800~1 100 m; the higher the paleotopography, the larger the eroded thickness. The source rocks in No.2 member and No.4 member of Funing formation on hanging wall has reached the oil threshold, respectively, in late Dainan formation and early?middle Sanduo formation, after that, a great amount of which are matured and generate hydrocarbon; the source rocks of No.2 member of Taizhou formation on footwall reach the oil threshold in early?middle Sanduo formation, but they are still in immature or low?mature state for shallow burial conditions in late period