Abstract: The oxygen evolution reaction on NiCO₂O₄ and Nd_0.8 Sr_0.2 CoO₃ have been investigated. Tafel slopes, apparent reaction orders of OH^- and apparent activation energies are determined by the steady-state method. Analysis of the transient characteristics of the linear potential swept diagrams is being emphasized. Summing up both the steady-state and transient characteristics, a preliminary mechanism of oxygen evolution reaction on these electrodes is propounded. Computer modeling calculations of this mechanism have been carried out. The results obtained are in fair agreement with the experimental curves.