A trifluoroacetate metal-organic deposition (TFA-MOD) derived (Y0.77Gd0.23)Ba2Cu3Oy [(Y,Gd)BCO] thin film was prepared on an annealed CeO2-buffered R-Al2O3 substrate (25 × 25 mm) for high-power high-temperature superconducting (HTS) transmit filter. The fluctuation of the superconducting transition temperature (Tc) and the self-field critical current density (${J}_{\mathrm{c}}^{\text{sf}}$) were small, which indicated a uniform thin film. The (Y,Gd)BCO thin film showed high ${J}_{\mathrm{c}}^{\text{sf}}$ and low surface resistance (Rs). The average ${J}_{\mathrm{c}}^{\text{sf}}$ at 77 K and Rs (21.8 GHz) at 77 K were 8.9 MA/cm2 and 2.3 mΩ, respectively. The TFA-MOD derived (Y,Gd)BCO thin film on an annealed CeO2-buffered R-Al2O3 substrate is thus a promising candidate material for high-power HTS transmit filters.