Electroreduction of peroxodisulfate anion on an electrochemically polished Cd(0001) plane in aqueous NaF solution with different additions of Na2S2O8 was studied by rotating disc voltammetry. The rate of electroreduction of S2O82- depends on the electrode potential and base electrolyte concentration, i.e. on the thickness of the diffuse layer. The kinetic current densities at E = const have been obtained by the Koutecky-Levich method and used for the determination of the apparent rate constant values of electroreduction of S2O82-anion. The psi(0) potential values obtained according to the Gouy-Chapman-Grahame (GCG) model have been used for the construction of corrected Tafel plots, which were linear at E -psi(0) < -1.1 V (SCE). The value of the charge transfer coefficient alpha decreases somewhat with the concentration of the base electrolyte solution (0.18 less than or equal to alpha less than or equal to 0.22), but the value of alpha is practically independent of the concentration of S2O82- ions if c(NaF) = const.