LaCol yFeyO3(y=0,0.1,0.2,0.3,0.4,05)perovskites were prepared by the sol-gel method and characterized by XRD,BET,SEM,in situ DRIFTS,and TPR.With this preparation method,a good inclusion of the substituting cation in the B-site is reached,maintaining the orthorhombic crystalline structure,and modifying the volume of the unit cell.The catalytic activities were promoted with Co substitution,and increased with higher X values.Higher surface area and reducibility were obtained with increased Co dopants.The CO-adsorption of NO and O2 at 100℃ showed the improved NOx adsorption ability with more amount of Co doped.Analysis by synthesizing the characterization results and catalytic activity data shows that large surface area,lower reducibility and easy adsorption of NOx are favorable for the NO oxidation by Co inserted.