The electrode performance of the molten carbonate fuel cells depends on the electrolyte occupation of pores. Therefore, we have tried to control the electrolyte occupation of anode and cathode pores within appropriate ranges by optimizing the anode and cathode pore distributions. The mean pore diameter of cathode was enlarged to circa 8um compared that of anode of circa 5um, which enhanced and stabilized the cell performance. Cell voltages at 150mA/cm2 were maintained above 0.8V for more than 5000h.