Perovskite oxide LaCoO_3 methane catalytic material was synthesized with citric acid complexation and bubbling method. The effect of doped cerium was studied on the series of La_(1-x)Ce_xCoO_(3+δ) materials by means of BET, XRD and SEM techniques. Their catalytic behaviors were studied with methane catalytic complete combustion as probe reaction. The results show that doped cerium has great effect on crystal phase formation. When doped cerium is less than 0.3 ((molar) ratio), the crystal phase of oxide has little changed. When doped cerium is up to 0.5, Co_3O_4 phase is obviously discovered and the perfectibility of LaCoO_3 perovskite crystal phase is deteriorated. When x is over 0.7, perovskite crystal phase is weakened or completely disappeared. Considering the crystal phase of oxides, the optimum doped cerium is about 0.3. The perovskite oxides can be formed at a low calcinations temperature of 700 ℃. When x is 0.3, the highest catalytic activity of T_(10%) (390 ℃) and T_(90%) (603 ℃) is obtained on the series of La_(1-x)Ce_xCoO_(3+δ) materials calcined at 800 ℃. Perovskite oxide LaCoO_3 methane catalytic material was synthesized with citric acid complexation and bubbling method. The effect of doped cerium was studied on the series of La_ (1-x) Ce_xCoO_ (3 + δ) materials by means of BET, XRD and SEM techniques. Their catalytic behaviors were studied with methane catalytic complete combustion as probe reaction. The results show that doped cerium is great than about 0.3 ((molar) ratio) When x is over 0.7, the perovskite crystal phase is weakened or completely disappeared. Considering the crystal phase of oxides, the optimum doped When x is 0.3, the highest catalytic activity of T_ (10%) (390 ° C) and T_ (90%) is about 0.3. The perovskite oxides can be formed at a low calcinations temperature of 700 ° C (603 ° C) was obtained on the series of La_ (1-x) Ce_xCoO_ (3 + δ) materials calcined at 800 ° C.