The powders of LaNi0.6Fe0.4O3–δ (LNF) and Ce0.9Gd0.1O1.95 (GDC) were prepared via a sol–gel method. LNF powder was characterized by X-ray diffraction (XRD). The morphology of the piece sections of LNF and GDC ceramics was determined by scanning electron microscopy. A limiting current oxygen sensor using GDC as a solid electrolyte layer and LNF mixed ion-electron conductor as a dense diffusion barrier was developed via a Pt liquid agglutination method. The influences of temperature and oxygen content on the oxygen sensitive characteristic for oxygen sensor were investigated. Based on the XRD result, LNF powder has a single perovskite structure. LNF and GDC ceramic both have a greater sintered density and a lower porosity. The sensor has a good stable current plateaus at 740–820 ℃ as the oxygen concentration increases from 0.3% to 1.1%. Besides, the response/recovery time of oxygen sensor are 18 and 23 s, respectively, showing the good response characteristics. Also, the limiting current is linearly related to the oxygen concentration and the temperature (T–0.5).