Recently, the beneficial effects of the fibrous cathode using mixed ionic and electronic conducting (MIEC) materials have been reported. Although many researchers deal with the performance enhancement by applying the fiber structure to SOFCs, a stability research under operating conditions is sparse. In mixed conducting perovskites-type cathode system, the degradation commonly results from the following reasons. Firstly, the particle coarsening occurs during the operation, which is a dominant contribution to performance degradation for cathode materials. Secondly, the Sr-enrichment on the surface of cathode blocks the oxygen reduction reaction sites and decreases the effective surface. In our previous work, a fibrous cathode with embedded ionic conducting particles has been successfully fabricated by a simple and easy approach using an electro-spinning method. In this work, we conducted the stability test using a half-cell under cathodic polarization (700 ℃, 500 mA·cm<sup>-2</sup>, 120 h) to ensure the degradation phenomenon from the cathode.