Dawsonite is an orthorhombic, hydrated sodium aluminium carbonate, appearing as radial, bunchy, trichoid platy collective and so on, filling in the pores among the grains, or as replacement of feldspar and detritus partly or on the whole, dawsonite is a kind of authigenic mineral which formed latest. High CO₂ pressure, temperature range between 25~100℃ and alkaline—weak acidic fluid is necessary for generating dawsonite. The solubility experiment for dawsonite indicated that under the stratigraphic condition, the temperature for the solution of dawsonite in 100~150℃,and the generation of some carbonate and other new mineral can occur after the reaction. In 100℃, the stability of dawsonite and generation of carbonate mineral indicate that dawsonite can exist stable in stratum, and can make the chance for the realization of the underground storage for CO₂.