Some basic matters concerning with the heat effect at electrode–electrolyte interface are briefly introduced in this paper. They include the concepts and definition about the electrochemical Peltier heat (EPH) and the Peltier coefficient for the electrode process, the absolute scale, the fundamental equations on this scale for thermoelectrochemistry, and the issues of the entropy changes on this scale and EPHs for the standard hydrogen electrode reaction as well as other standard electrode reactions. The EPH of electrode–electrolyte interface is specially emphasized to be a quantity related to reversible process; thereupon it can be measured and also be calculated by the change in the function of state, or entropy, on the absolute scale. The changes in entropy on the absolute scale, EPHs and the electrochemical Peltier coefficients for some of the most common standard electrode reactions in aqueous solution at 298.15K are given.