Abstract: CVD-SiC coated C/ SiC composites were implanted with boron ions by plasma source ion implantation toimprove it s oxidation resistance. Depth profile of the boron ions in the boron-implanted SiC-C/ SiC composites waschecked by Auger elect ronic energy spect rum. Oxidation test s of the SiC-C/ SiC composites were performed in flowing dry air at 1300 ℃. The sample with boron ion implantation exhibit s lower mass loss than those without boron ionimplantation. The surface morphology of the sample was obtained by scan elect ronic microscope. Some air bubbleswere observed in the coating. Flexural st rength test s show that the mechanical property of ion-implanted sampleschanges little compared with that of the samples without ion implantation.