Single cells of solid oxide fuel cell(SOFC) with thin film composite interlayers were fabricated in order to improve charge transfer reaction in the electrode/electrolyte interface. Yttria-stabilized zirconia(YSZ) slurry was prepared by mixing YSZ powder with typical organic dispersants, and the optimum YSZ slurry composition for the interlayer dip-coating was determined by employing backscattering flux measurements. By the insertion of interlayer, a denser YSZ electrolyte layer could be prepared and the electrochemical performance of SOFC could be enhanced significantly.