A series of (AO) (ABO 3 ) n (A = La, B = Ni, n = 1 4) type mixed oxides are synthesized and characterized by means of XRD, XPS, IR, TPD, TPR. Their structure characteristics and redox properties are studied. The nonstoichiometry (λ) of oxygen and the valence of transition metal Ni are determined by using chemical analysis method. The catalytic activities of this series of mixed oxides for complete oxidation of CO and CH 4 are examined and the relationships among activity, composition and structure are discussed.