The existing forms of Cr(Ⅲ) complexes in aqueous solution and ［1ChCl∶2EG］/CrCl3·6H2O ILs containing 0.1～0.6 mol·L-1 CrCl3·6H2O, respectively, were investigated by using ESI-MS and UV-Vis absorption spectra. The results showed that Cr(Ⅲ) combined with Cl－ and H2O to form ［Cr(H2O)nCl6-n］n-3 in both cases, and the dominant species of which were affected by the concentration of CrCl3·6H2O. Concretely, the dominant complexes of Cr(Ⅲ) in aqueous solution are ［Cr(H2O)6］3+ and ［Cr(H2O)5Cl］2+, and the UV-Vis absorption spectra is observed to redshift with an increase in the concentration of CrCl3·6H2O, along with enhancement in the mole fraction of ［Cr(H2O)5Cl］2+. By contrast, the dominant species of Cr(Ⅲ) in ［1ChCl∶2EG］/CrCl3·6H2O ILs are ［Cr(H2O)2Cl4］－ and ［Cr(H2O)3Cl3］. Increasing the concentration of CrCl3·6H2O results in gradual color change of the solution from light orange-red to dark green, blue shift of the UV-Vis absorption spectra, and higher mole fraction of ［Cr(H2O)3Cl3］. Both the coordination number of Cl－ and H2O that complexes with Cr(Ⅲ) as well as the relative content of the dominant complexes of Cr(Ⅲ) in solvent is proved to be influenced by variation in the concentration of CrCl3·6H2O.