Abstract: In this paper,the amount and compositions of the gaseous and liquid hydrocarbon products and their evolutionary regularities are studied on the bases of hydrocarbon generation and expulsion modellings on two brown coal samples simultaneously. Combined with recently documented achievements,the authors have proved the evident influence of reactive pressure upon the amount and compositions of gaseous and liquid hydrocarbon products. At the same time,the authors discuss on the capacity of oil generation and expulsion derived from brown coal,the mechanism and effects of hydrocarbon migration,and hydrocarbon maturation and evolution.