Abstract: One kind of HRu₄O₈ microrods were fabricated with solid-state calcination and the proton exchange method. The morphology and crystal structure of HRu₄O₈ microrods were characterized with X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and so on. The catalytic activity of HRu₄O₈ was evaluated with the linear scanning voltammetry, cyclic voltammetry, Tafel plot, chronopotentiometry and other electrochemical methods. The results showed that the preparation of HRu₄O₈ with the RuO₂ nanoparticle precursor resulted in a significant increase of the electrochemical active surface area. HRu₄O₈ exhibited excellent electrocatalytic activity towards OER with an overpotential of only 208 mV at 10 mA/cm², lower than that of RuO₂ nanoparticles(276 mV). Moreover, HRu₄O₈ also presented outstanding stability for 10 h without apparent degradation. Such work sheds light on new perspectives for designing highly active electrocatalyst of water splitting.