Here we introduce and outline some advances of gas hydrate dissociation and fate of methane in marine sediment.A gas hydrate accumulation in sediments is related to a geological structure and/or stratigraphic trap, and the kinetic control for gas hydrate dissolution is mass transfer and that of dissociation is heat transfer. There are three main release types of methane release from gas hydrates within the accretionary sediment, such as distributed migration, focused migration and massive methane release.There now exists compelling evidence that anaerobic oxidation and aerobic oxidation of methane are two main reaction pathways in marine sediments and waters. Methane release by hydrate destabilization has been proposed to have four ultimate sinks, namely reformation gas hydrate, precipitation of carbonate minerals and formation of unique clam or tubeworm communities, transformation carbon dioxide,discharge into the atmosphere. The evidence preserved in the fossil sedimentary deposits, including sedimentary mictrostructures, nodular or encrusting diagenetic carbonates, specific benthic fauna and oxygen and carbon isotopic compositions of carbonates, might have registered the past occurrence of gas hydrates.