Impregnation or infiltration are terms used to describe the process of depositing nano particles into electrode structure. Using infiltration of nano particles, cell performance can be improved due to increased three phase boundary (TPB) where electrochemical reactions occur. So, by infiltration of dispersed particles, we can expect more performance due to increased surface area. But, many literatures related to infiltration for improving performance deal with almost air electrode infiltration. Commonly, Ni and electrolyte materials are used as fuel electrode. To infiltrate nano particles, fuel electrode needs appropriate porosity and maintains porous structure. But, it is hard for fuel side electrode to maintain its structure because Ni can be oxidized to NiO easily during heat treatments. So, not to be reoxidized, reduction of fuel electrode was done at the last process. And, one side reduction is necessary because air electrode can be decomposed in low pO2 condition. To infiltrate dispersed nano particles, we used urea precipitation method because it gives the solution precipitating ligands to whole solution so that precipitations occur homogeneously. Because urea needs decomposition time, urea concentration should be higher than cation concentration so as to precipitate whole cations. Thus, urea/cation concentration ratio and aging time were chosen as variables. Infiltration was conducted to Ni-YSZ support whose air electrode side was blocked by epoxy. After infiltration, epoxy was burned out at 600^oC with fuel electrode flowed by H2. Finally, electrochemical properties were investigated by I-V curve, EIS and DRT.