Huangqiao carbon dioxide gas field in North Jiangsu Basin have the following characteristics: deep gas fields are associated with shallow ones, marine gas fields are coupled with continental ones, and several gas reservoirs are combined. Carbon dioxide in Huangqiao area mainly comes from deep mantle, mixed with a little thermal metamorphism and a little organic carbon dioxide in shallow formation, and helium and nitrogen gas mainly come from mantle. There is a good time space matching relationship between carbon dioxide gas reservoirs and great rifts, magma and volcano activity, which forms the special carbon dioxide gas reservoir mode for Huangqiao. This mode has good sealing, trapping and preserving conditions, but its gas source differs from traditional hydrocarbon gas reservoirs. So the inorganic gas reservoir exploration should not only be confined in petroliferous basins, but also focus on mantle liquid rising lane of the volcano active area, mantle plume, deep earthquake region in an extensional environment, especially shear zone out of basins, crater containing mantle derived xenoliths where, according to the conventional organic gas generation theory, the hydrocarbon gas reservoir can not exist.