[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 SO42- exhibited as an "M" shape pattern

while variations in Na+

Mg2+ and HCO3- were not significant. No carbonate (CO32-) 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.