The electronic energy level of lanthanum compounds plays an important role in oxygen reduction reaction (ORR) electro-catalytic process. In this work, three lanthanum compounds, LaOHCO3, La2O2CO3 and La2O3, were synthesized via an in-situ urea hydrolysis method, followed by annealing at different temperatures. Among these lanthanum compounds, the layer-structured La2O2CO3 has the minimum bandgap and a moderate value of conduction band (CB) and valance band (VB). Electrochemical measurements in 0.1 M KOH solution show that compared with the other catalysts, La2O2CO3 exhibits the best electro-catalytic activity with lowest HO2- production and highest durability for ORR, which proves the close correlation between electronic energy level and electro-catalytic ORR activity. During the ORR process over La2O2CO3, some covalent electrons from VB are first excited into CB and then transfer into the unoccupied ?*2p orbitals of active oxygen molecular, leading to a strengthen oxygen adsorption and promoting the reduction of oxygen. Moreover, La2O2CO3 has an ability of chemical disproportionation for hydrogen peroxide (HO2-), and the produced HO2- at the energy level of O2/HO2- level can undergo prompt chemical disproportionation into O2 and OH- species. The generated O2 at this stage is adsorbed on the catalyst surface, which can be utilized for further oxygen reduction again.