Solubility of 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfanilamide] ([Bmim][NTf2]) and 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) in supercritical carbon dioxide (scCO(2)) using ethanol (EtOH) and ethylene glycol (EG) as a double cosolvent was measured at 40 degrees C and pressure from 8.0 to 15.0 MPa which was shown as the mole fraction of ionic liquids (ILs). The influence of ratios of EtOH to EG, pressures, concentrations of the cosolvent, and anions on enhancing the solubility of ILs in scCO(2) was investigated in this paper. The ability of the cosolvent with different ratios of EtOH to EG to enhance the solubility of [Bmim][Ac] followed the order y(1)/y(2) = 10:1 > y(1)/y(2) = 20:3 > y(1)/y(2) = 5:1 > y(1)/y(2) = 20:1. The maximum solubility of [Bmim][Ac] in scCO(2) was 5.6 x 10(-4), which was about 30 times higher than its solubility using EtOH as a single cosolvent. The ability of the cosolvent with different ratios of EtOH to EG to enhance the solubility of [Bmim][NTf2] followed the order y(1)/y(2) = 20:1 > y(1)/ y(2) = 10:1 > y(1)/y(2) = 20:3. The maximum solubility of [Bmim][Ac] in scCO(2) was 2.4 x 10(-4), about 1.5 times higher than its solubility using EtOH as a single cosolvent. The difference in ability to enhance solubility could be explained by solubility parameters. Finally, the modified Chrastil model, modified Mendez-Santiago-Teja model, and modified Adachi-Lu model were employed to correlate the solubility data. The modified Chrastil model possessed the highest accuracy whose average absolute relative deviations were 2.88-7.06%.