Abstract: In this paper,the secondary hydrocarbon generation mechanism of the Upper Paleozoic coal in the South Huabei Basin was studied using a new kind of quantitative evaluation method for gas source rock.Two series of thermal simulation experiments were conducted,that is,the successive hydrocarbon generation thermal simulation and the stepwise hydrocarbon generation thermal simulation(simulating the process of subsidence uplifting subsidence).Besides,the characteristics of secondary hydrocarbon generation for coal rock were also discussed.