Metal-matrix and oxide-matrix composites containing Co3O4 as the dispersed phase were electrodeposited and tested as anodes for oxygen evolution reaction from basic medial The limiting volume fraction of Co3O4 for composites with different matrices was 0.4 (Ni), 0.2 (PbO2), 0.15 (Tl2O3) and 0.05 (Pb). However, the electrocatalytic activity of the composite materials was not only controlled by the Co3O4 content, as the overpotential for oxygen evolution reaction varied in the order. Tl2O3-matrix < PbO2 < Pb < Ni. In addition to lower overpotential, oxide-matrix composites exhibited better performance in long term electrolyses.