Abstract: Based on a series of thermal simulating experiments carried out for the Huangxian lignites and the Maoming oil shales and their products data analysis, some knowledge is concluded In this paper:
1) ThenC₂₁^-/nC₂₂⁺ ratio of the expulsive hydrocarbon is higher than that of the residual hydrocarbon. The βα/βα ratio for sterane, terpane differ geetly, especialy for C₂₇ sterane C₂₉ sterane and C₂₉ terpene, C₃₀ terpane. Expulsion of naphthalenes, dighenyles, fluorenes with low olecular weight is in preference to that of other polycyclicaromatics. Heavier aromatics such as pyrenes, chrysenes and fluoranthenes are difficult to migrate.
2) Comperison between the remaining hydrocarbon and the expulsive hydrocarbon during different tempraturestages shows that their differences decrease with the increasing expulsion of the hydrocarbon.

Key words: Huangxian lignite, Maoming oil shale, hydrocarbon expulsion process, thermal simulation, initial migration