Gas hydrate is a very complicated reservoir system characterized of temperature, pressure, gas composition, pore-water geochemical features, and gas sources, gas hydrate distribution within the gas hydrate stability zone. Temperature, pressure and the gas composition of the sediments were suitable for gas hydrate formation in the gas hydrate reservoir system of Shenhu Area, north slope of South China Sea. The high-resolution seismic data and the gas hydrate drilling getting high concentrations of hydrate (>40%) in a disseminated form in foram-rich clay sediment showed that gas hydrate is distributed heterogeneously at all spatial scales in all drill holes, and the hydrate-bearing sediments ranged several ten meters in thickness are located in the lower part of gas hydrate stability zone (GHSZ), just above the bottom of gas hydrate stability zone (BGHSZ). It is likely seem that the methane to crystallize gas hydrate is from in-situ microbial methane.