It was found that the electrical properties of CeO2/La 2O3 stack are much better than a single layer La 2O3 film. A thin CeO2 capping layer can effectively suppress the oxygen vacancy formation in the La2O 3 film. This work further investigates the current conduction mechanisms of the CeO2 (1 nm thick)/La2O3 (4 nm thick) stack. Results show that this thin stacked dielectric film still has a large leakage current density; the typical 1-V leakage can exceed 1 mA/cm 2 at room temperature. The large leakage current should be due to both the oxide defect centers as well as the film structure. Results show that at low electric field (<0.2 MV/cm), the thermionic emission induced current conduction in this stacked structure is quite pronounced as a result of interface barrier lowering due to the capping CeO2 film which has a higher k value than that of the La2O3 film. At higher electric fields, the current conduction is governed by Poole-Frenkel (PF) emission via defect centers with an effective energy level of 0.119 eV. The temperature dependent current-voltage characteristics further indicate that the dielectric defects may be regenerated as a result of the change of the thermal equilibrium of the redox reaction in CeO2 film at high temperature and the drift of oxygen under the applied electric field.