Abstract: The relationship between the vitrinite reflectance of residual matter and hydrocarbon yield rate was established through pyrolysis experiments that simulated maturation of organic matter. R_o values calculated through pyrolysis simulation indicative of different maturities were compared to natural evolution profiles. Using these data, an Easy%R_o model and the relationship between H/C ratio and R_o of kerogen were applied based on the multi-stage evolution of vitrinite reflectance. We put forward an Easy%R_o correction chart, a multi-stage H/C correction approach and the formula for the pyrolysis simulation experiment. The hydrocarbon generation model rebuilt using the corrected vitrinite reflectance was much closer to the natural evolution model.