Abstract: In order to enhance the ablation resistance of C_f/SiC composites in high temperature, Ir films on banding and tubular specimen of C_f/SiC composites was made with metalic organic chamical vapour deposition process.The results indicate that after the deposition, the mechanical property of the specimen is not deteriorated and the deposited Ir films show metallic brightness.The excessive oxygen content in the films resulted from O₂ flow during the deposition process is reduced remarkably with post treatment of purification, which provides a new approach to high-purity Ir films.