Abstract: Vitrinite-rich brown coal was sampled for our artificial maturation experiments to set up a corresponding relationship between telocolinite vitrinite reflectance and heating temperature (R°-T_PY). By using such a relation, we can assess the maturities of all kinds of source rocks during the artificial maturation. It is also noted that by using telocolinite vitrinite reflectance as a maturitty parameter, the evolution and oil generation behaviors of source rock exhibited in artificial maturation are quite similar to those observed in geological condition. Thus, the experimental achievements of artificial maturation can be easily applied in the quantitative assessment of subsurface petroleum generation without any correction.