Water-dissolved gas is a kind of unconventional gas. To further analyze the economic value of water-dissolved gas in the Quaternary of the Sanhu of Chaidamu Basin, the authors preliminarily study the classification of water-dissolved gas according to the change of gas/water ratio and after quantitatively processing the gas bearing saturation using the gas bearing saturation model derived by conductivity expression in a gas bearing shaly sandstone dual porosity model along with referencing practical test results. Water dissolved gas can be divided into four types. It is of economic value when, according to the static economic evaluation, the gas/water ratio is more than 20 m³/m³ under the present economic and technological conditions. The reservoir formation of water-dissolved gas with high GWR are controlled and influenced by structural trap, development degree of gentle slope belts, steep slope zone etc.