The SO2 absorption capacities of two ionic liquid mixtures formed by 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]) and 1-ethyl-3-methylimidazolium thiocyanate ([Emim][SCN]) were studied. The ionic liquid mixtures with different molar ratios of [Emim][Cl] and [Emim][SCN] (1:1 and 1:2) can be easily synthesized. The SO2 solubility in the two mixtures was investigated under different conditions. The results demonstrated that these mixtures were efficient for SO2 absorption. [Emim][Cl]-[Emim][SCN](1:1) captured 0.50 g/g solvent at 20 degrees C and 0.10 atm. Under the low SO2 partial pressure (1960 ppm), the [Emim][Cl]-[Emim][SCN](1:1) could capture 0.11 g/g solvent. The high SO2 absorption capacity is mainly due to the strong charge-transfer interaction of the sulfur atom of SO2 with the anions ([Cl](-) and [SCN](-)). Moreover, the solvent [Emim][Cl]-[Emim][SCN](1:1) can be reused.