Abstract: Controlled by geothermics, the vitrinite reflectance of samples shows an exponential relation with depth. Based on abundant data, the Cenozoic maturity curve of Jiyang Depression was simulated in this paper. Furthermore, according to the difference in the paleogeothermal information and the paleotemperatures on the surface between the Mesozoic and Cenozoic, the Mesozoic maturity curve in this area was calculated. This also provided a reference for analyzing and determining the maturity of source rocks. Based on this, accompanied by the relationship between thermal history and structural fluctuation, two methods of using vitrinite reflectance to calculate the strata denudation were introduced and applied in the calculation of strata denudation for unconformity between the Mesozoic and Cenozoic in Jiyang Depression. Our investigation indicates that more than 3 000 m rocks were eroded as a result of the Indonesian movement that happened in Late Triassic. The eroded strata include the whole Early Triassic and Middle Triassic strata and a part of the top of Carboniferous. The absence of the Triassic in the a of Jiyang Depression was caused by denudation.