[Objective] This research focuses on the response of soil inorganic ions to CO₂ leakage.[Methods] We grew two crops including buckwheat (Fagopyrum esculentum) and mung beans (Vigna radiate)in the artificial climate box with five simulated CO₂ concentration gradients of 0 (control group), 10 000, 20 000, 40 000, 80 000 μl/L, to observe the variations of soil inorganic icons and plant growth.[Results] With the increase of CO₂ concentrations, Cl^-, K⁺, Ca²⁺ decreased firstly and then increased. The trend of SO₄^2- exhibited as an "M" shape pattern, while variations in Na⁺, Mg²⁺ and HCO₃^- were not significant. No carbonate (CO₃^2-) was found during the testing. Photosynthetic rate and biomass of buckwheat and mung beans were the maximum when the concentration of CO₂ reached 10 000 μl/L.[Conclusion] Increases in the concentration of CO₂, can influence the pH value and carbon balance of the soil, and result in the precipitation of ions. In addition, the rise in CO₂ concentration affects the growth of crops and microbial activity, and changes the absorption and metabolism to soil ions.