AbstractCo3O4 nanomaterials with different morphology were easily prepared by calcining Co(OH)2 precursor at different temperatures. The obtained mesoporous Co3O4 with special surface structure had excellent catalytic activity for methane combustion. The specific rate of methane combustion over mesoporous Co3O4 reach up to 1.8 μmol g−1 s−1 at 300 °C. It is close to the specific rate over the supported noble metal catalysts and higher than that over the transition metal oxide catalysts reported in the literature. TEM images, H2‐TPR profiles and XPS spectra analysis testified that some vacancy, antisite, dislocation and grain boundary defects in narrow junction regions around the pore openings may be the origin of the excellent catalytic activity of the mesoporous Co3O4 nanomaterials.