Abstract: The volcanic body and intrusive rock body shaped by volcanic activity can form thermal source kitchen bodies into depositional rocks. In terms of sequence relations between volcanic body or intrusive body and source rocks. it can be divided into upper,middle and lower kitchens,which become a kitchen-like hydrocarbons generating model. So it is the volcanic activities that offer the earth's deep inorganic origin non-hydrocarbons gases(CO,CO2,H.etc.) into sedimentary basins. The gases may compound-generated mechanism occurring in the cap rocks of the basin. In addition,the inorganic gases from the deep of the earth contain methane carbon isotope of ≥-25‰,methane homolog carbon isotope composition could generate re-successional arrangement of inorganic methane gas followed by shaping inorganic methane gas reservoir. The volcanic activity conveys magmatic rock for a sedimentary basin,in which the hydrocarbon material such as methane, alkene, alkyne, etc. occurs in mantle rock, while crystalline rock in magmatic rock contains methane material,and exist the trend that the hydrocarbon content increases with the gravity increasing, so is volcanic rocks in magnetic rock, including carbon atomicity increasing. By volcanic activities a sedimentary basin may also get hydrothermal fluid, some metal elements (Fe, Mn, Zn, Cu, Pd) carried by water may accelerate the amounts of hydrocarbons generation. Therefore, it is indicated that the sedimentary basin with two-component cap structure appearsa catalytic hydrocarbon generation model.The conclusion shows that the effect of a volcanic activity on a basin with two-component cap structure could increase or accelerate its hydrocarbon generation. The multiple models give rise to mechanisms of organic, synthetic and inorganic hydrocarbon generation in basins with two-component cap structures.

Key words: volcanism, sedimentary basin, organic matter evolution, hydrocarbon generation model, organic origin, inorganic origin