Dense and thin Sm 0.5Sr 0.5CoO 3-δ (SSC) interlayer film was fabricated by a pulsed laser deposition (PLD) method on the Sm 0.2Ce 0.8O 2-δ (SDC)/La 0.9Sr 0.1Ga 0.8Mg 0.2O 3-δ (LSGM) bi-layer electrolyte film on a Ni-Fe metallic anode for intermediated temperature solid oxide fuel cells. Effect of SSC interlayer on the power generation property and optimum fabrication condition of SSC interlayer has been investigated. By inserting SSC interlayer, power generation property and thermal cycling durability was improved due to improved contact strength and expanded oxygen ion conduction path. Particularly, the cell having 500 nm thickness SSC interlayer showed higher power generation property than that of the cell without interlayer. The maximum power density (MPD) of the cell was 1.99, 1.10 and 0.53 W/cm 2 at 973, 873 and 773 K, respectively. In addition, after thermal cycling treatment from 973 to 298 K (Heating and Cooling rate; 200 K/h), decrease in MPD was only 4%. The cell also showed a stable open circuit potential after re-oxidation treatment of anode at 673 K.