The solubilities Of CO2 in 1-butyl-3-methylimidazolium hexafluorophosphate and 1,1,3,3-tetramethylguanidium lactate at the temperatures ranging from (297 to 328) K and the pressures ranging from (0 to 11) MPa were determined. The extended Henry's law was applied to correlate the solubility data, and the thermodynamic properties such as standard enthalpy, standard Gibbs free energy, standard entropy, and standard heat capacity of these two systems were obtained. Experimental results showed that the solubilities Of CO2 in TMGL are slightly higher than those in [bmim] [PF6].