Abstract: In this paper, Co₃O₄ catalysts were prepared by the liquid precipitation method, and further was subjected to reduction-oxidation pretreatment to obtain Co₃O₄-RO. The catalysts were characterized by XRD, N₂-physisorption, Raman, H₂-TPR, XPS and O₂-TPD. Their catalytic activities in N₂O decomposition were tested on a fixed-bed continuous flow microreactor. The results show that both the crystallinity and the crystallite size of Co₃O₄-RO decrease in comparison with Co₃O₄. Especially the structural reconstruction resulted from the reduction-oxidation pretreatment weakens the Co-O bond and enhances the oxygen desorption capacity on the catalyst surface, which endows the Co₃O₄-RO a lower activation energy. Thus the catalytic activity of the Co₃O₄-RO in N₂O decomposition increases significantly. At the same time, Co₃O₄-RO shows strong resistance to O₂ (2% in feed)and H₂O (2.3% in feed).