Abstract: In this paper,the mudstone acoustic time difference method and the vitrinite reflectance method are used to calculate the Lower Cretaceous denuded thickness in the Santanghu basin.The results from the two methods fit well.It is revealed that the Lower Cretaceous denuded thickness is between 300m to 700m,and the denuded thickness increases from west to east.The Cenozoic sedimentary thickness,which is smaller than the Lower Cretaceous denuded thickness,cannot make up heat losses caused by denudation.Therefore,the Late Yanshanian movement played a destroying role in the generation of hydrocarbon.