Normal pulse voltammograms of the oxidation of ferrocyanide to ferricyanide were investigated in water and aqueous solutions of various electrolytes at temperatures above and below the freezing point of the solvent using a platinum microdisc electrode. A significant increase in the limiting current was observed on freezing, particularly in water without added electrolyte, and, in most cases, current vs. t(-1/2) plots gave a straight line, suggesting a diffusion-controlled mechanism. The concentration of ferrocyanide in the liquid phase localized at the electrode area in partially frozen solution was estimated from the slope by applying the diffusion coefficient of the ion in complete liquid at the freezing point or in the supercooled state, and this was compared with the concentration averaged in the bulk determined from the free induction decay (FID) signals of H-1-NMR measured under similar conditions to those of voltammetry. The degree of concentration determined from the limiting current was much higher than that estimated from the FID signals, particularly just before freezing was complete. Such a result indicates that a liquid microphase which concentrates solutes exists at or near the electrode in low temperature freezing solutions.