Natural gas hydrate is a kind of ice-like solid material composed of gas and water

mainly consisted in sea floor and permafrost with low temperature and high pressure. The gas can either be microbially produced or catagenic gas from deeper sediments. Although gas hydrate within benthal deposit has the ability to construct seafloor by cement sediments

it has the potential to store enormous volumes of gas and water and then release the gas and water when the hydrate’s equilibrium conditions are brocken

which can cause sediment transport leading to submarine landslide. Equilibrium conditions can be brocken by sea level lowing

continuing sedimentation

earthquake and ocean drilling. In either case

some of the solid gas-water matrix decompose. Released gas and water volume exceed the volume occupied by the hydrate

so the internal pressure rises dramatically if large volumes of hydrate are decomposed. Part of the rigid sediment is converted to a gas and water rich

relatively low density mud. When the internal pressure

due to the presence of the compressed gas or buoyancy

is sufficient high

the overlying sediment may be lifted and slide on a plane producing landslide. The less dense gas-cut mud can also ejected violently in some places.There are more than twenty submarine landslides found relevant to gas hydrate decompose

they distributed in almost all the continental edges. Sea floor geological survey and analysis indicate that this special landslide has three features commonly: occurred on the slope grade less than or equal to 5°; depth of the landslides’ top close to the bottom of hydrate stability zone; no hydrate in the sediments below landslides.Submarine landslide related to gas hydrate decompose is a new direction for geo-hazard researchers; the research in our country is nearly blank. Following is the hot research aspects: quantifying mechanical features of sediments containing gas hydrate

sediments’ dynamic response to the changes of physical and chemical conditions caused by gas hydrate forming and decompose

triggering mechanism research and simulation.