Natural gas resource of low porosity and permeability reservoir is the main body of natural gas exploration and development of current and future period in China, with the characteristics of largescale hydrocarbon accumulation. This paper focuses on the large-scale gas accumulation characteristics and distribution law of this type gas resource, and it is recognized that reservoir-forming factors have the characters of development and change in a large scale, which is the foundation of gas accumulation in a large scale. The main types of gas accumulation in a large scale are the “pancake type” outside and “cluster type” inside;the scale“energy storage” in burial period and scale“exhausting gas” in uplift stage are the important gas source;the volume flow and diffusion flow filling are the main migration and accumulation modes. The distribution of low porosity and permeability gas reservoir is close to source , and reservoir combination mainly contains two types,which are large area and large scope types, and the stratigraphic and lithologic traps are the main type. The synclinal area of marine cratonic basin, the broad slope zone of intracontinental DownWarped basin and slope slow wing area of foreland basin are the main areas of large scale accumulation of this kind of natural gas resources. The recognization of large scale gas accumulation of low porosity and permeability gas resources has been put forward, which prompts the discovery potential of natural gas resource, expands the range of exploration, provides the theoretical basis for objective evaluation of the total amount and distribution of natural gas resources,and promotes the large gas field effective discovery in China.