The temperature dependence of the potential, dE/dT, of some redox couples was investigated in different amide-type ionic liquids. The half-wave potentials of the redox couples were determined by DPV (differential pulse voltammetry). The halfwave potentials varied linearly with the temperature from 298 to 328 K in the ionic liquids. The reaction entropies (ΔrcS0) of the redox couples were calculated from the dE/dT values. ΔrcS0 of the redox couples with positive charges were affected mainly by the anions of ionic liquids. In contrast, ΔrcS0of the redox couples with negative charges depended on the cations of ionic liquids. These results suggest the coulombic interaction between the redox couples and the ions with the opposite sign of charge to those of the redox couples is a dominant factor determining ΔrcS0.