The electron paramagnetic resonance spectra of the chelate-based ionic liquid [C10mim][Cu(F6-acac)3] in different solvents have been obtained at 120 K. It was found that the values of the 63Cu hyperfine coupling constants (AIL) of [C10mim][Cu(F6-acac)3] in molecular solvents were from 116 to 180 Gauss. Moreover, the AIL values in general ionic liquids are more complicated, and two sets of peaks can often be observed in their electron paramagnetic resonance spectra. Based on the Kamlet–Taft parameters, relative permittivity, the experimental results were discussed in terms of solvation effect and coordination of the solvents.