New experimental results are reported for the solubility of carbon dioxide (CO2) in nitrate- and thiocyanate-based ionic liquids (ILs) at temperatures ranging from 298.15 to 333.15 K and pressure up to 4.5 MPa. The studied ILs are 1-methyl 3-octylimidazolium thiocyanate [Omim] [SCN], 1-methyl 3-hexylimidazolium thiocyanate [Hmim] [SCN], 1-methyl 3-octylimidazolium nitrate [Omim] [NO3], and 1-butyl 3-methylimidazolium tetrafluoroborate [Bmim] [BF4]. The solubility measurements are performed in a known volume stainless steel equilibrium cell. The experimental data indicated the solubility of CO, decreases with increasing of temperature. Henry's constant are calculated from the solubility data. The experimental results for CO, solubility are correlated with the extended Henry's law and Pitzer virial expansion using binary parameters. The correlation results of gas solubility are agreed with the experimental data.