Dense La0.81Sr0.09MnO3 (LSM) electrode was prepared by a laser ablation method and electrochemical measurements were carried out. The electrode impedance was proportional to the film thickness and almost independent of the oxygen partial pressure. Steady-state polarization characteristics were measured and oxygen ionic conductivity of LSM as calculated using Hebb-Wagner polarization method. The slopes of log i - log a(o), curves were calculated to be - 1/2. These results suggest that the cathodic reaction mechanism of the dense LSM electrode is quite different from that of porous electrode.