In this work, nickel and gadolinium-doped ceria (GDC)-infiltrated lanthanum strontium titanate (LST) anodes are fabricated, and their electrode performances under a hydrogen atmosphere is investigated in terms of the Ni:GDC ratios and cell operating temperature. The Ni/GDC-infiltrated LST anode exhibits excellent electrode performance in comparison with the Ni- or GDC-infiltrated anodes, which is attributed to the synergistic effect of an extended triple-phase boundary length by GDC and good catalytic activity for hydrogen oxidation because of the Ni particles. The polarization resistances (RP) of Ni/GDC-infiltrated LST are 0.07, 0.08, and 0.12 Omega cm(2) at 800, 750, and 700 degrees C, respectively, which are approximately three orders of magnitude lower than that of the LST anode (68.5 52 cm(2) at 700 degrees C). The effect of Ni and GDC on the electrochemical performance of LST was also investigated by using electrochemical impedance spectroscopy (EIS). The anode polarization resistance (RP) is confirmed to be dependent on the content and dispersion state (microstructure) of the Ni and GDC nanoparticles.