Study on the increase of available lattice oxygen of VPO catalyst by adding Ce-Fe complex oxides was carried out using XRD, TPR and pulse reaction technique. For the oxidation of butane to maleic anhydride (MA) in the absence of gas-phase oxygen, the Ce-Fe promoted VPO catalysts have more available lattice oxygen and possess higher conversion and selectivity than that of the unpromoted one as well. It is supposed that the introduction of Ce-Fe complex oxides improves redox performance of VPO catalyst and increases the activity of lattice oxygen. However, the catalytic role of Ce-Fe complex oxides is still not clear.