This study has been carried out to evaluate the interest of chemical vapour deposition (CVD) (Si-B-C) layers to protect C/C and C/SiC materials against oxidation between 850-degrees-C and 1700-degrees-C. The deposits have been made in a hot wall reactor by a classical CVD technique. The coatings which were tested were either (Si-B-C) single layers, or SiC and (Si-B-C) multilayers. This study has shown that the control of the boron content of the (Si-B-C) layers and the thickness of each layer were essential. To achieve a good protection during several hours up to a temperature close to 1700-degrees-C, it seems that a trilayer SiC-(Si-B-C)-SiC is the most promising solution.