The wide existence of immature oils throughout the world especially in China broke through the hydrocarbon generation theory through kerogen thermal degradation. Studies have shown that soluble and insoluble organic matter are organically connected in the sedimentary rock, both contributing to hydrocarbon generation. In the diagenesis,kerogen can not produce oils, so immature oils derive directly from the soluble lipids. Hydrocarbon generation process through kerogen thermal degradation takes place mainly in the early catagenesis(R o= 0.2% ～1.2%), and the oils generated are normal. In the late catagenesis, hydrocarbon generation comes into wet gas stage(R o=1.2%～2.0%), with pyrrobitumen degenerating into high mature light oils and oils cracking into gases. In this paper,the author presented a new generating hydrocarbon and evolutionary model with soluble and insoluble organic matter both contributing to the generation of hydrocarbon.