Good hydrocarbon source rocks generally develop in orogenic belts in China. These source rocks formed in paleotrough environment, which is also the favorable environment of natural gas hydrate accumulation. Gas hydrate is of sealing hydrocarbon well. Hydrocarbon under the control of hydrate seal may migrate into neighboring areas, i.e. from the paleotrough areas (present-day orogenic belts) to platform areas (present-day basins). It is deemed that the source rocks in orogenic belts should have great contribution to hydrocarbon resource within basins. It is suggested that gas hydrate under the present southwestern sea area of Taiwan have an affinity with hydrocarbon reservoirs in neighboring areas. Also a considerable hydrocarbon resource in Sichuan Basin might be supplied by the orogenic belts of the basin margins.