Interfacial reactions at LSGM electrolyte and NiO-GDC anode interfaces were thoroughly investigated with Environmental Scanning Electron Microscopy (ESEM-PHlLIPS XL-30) and Energy Dispersive X-ray (EDX-Link XL30). According to the analysis, serious reaction zone was observed at LSGM/NiO-GDC interface. It was found that the reaction layer was originated from the chemical reaction between NiO and LSGM. The reaction products were identified as La deficient form of LSGM based perovskite and Ni-La-O compounds such as LaSrGa$_{3}$O$_{7}$ and LaNiO$_{3}$ from the X-Ray Diffraction (XRD, Philips) analysis. According to the electrical characterization, interfacial layer was very electrically resistive which would be the cause of high internal resistance and low power generating characteristic of the unit cell.