C/C composites are widely used as structural materials at high temperature in the aeronautic and space industries [1, 2]. A serious drawback, however, is that carbon in any form will react with oxygen, burning away rapidly at temperatures as low as 500 °C. Since the C/C composites are generally made of several types of carbon, each having its own reactivity to oxygen, the reactivity of carbon matrix would influence the oxidation performance of the C/C composites. In order to improve the oxidation resistance, carbon matrix has been partially or even totally replaced by other refractory materials which can be carbide or nitride. This family of materials were defined as hybrid carbon-ceramic composites, which can be made according to a two-step chemical vapour infiltration (CVI) procedure [3]. One material receiving considerable attention recently is the "functionally graded material" in which the material properties are continuously changed by gradually varying the dispersion-to-matrix ratio from one surface of the material to the other surface. Among these "functionally graded materials", one that consisting of silicon carbide (SIC) and carbon (C) was prepared by the chemical vapour deposition (CVD) technique through a codeposition process using multicomponent gas reactions. This material is called a nanocomposite because of the SiC of nm size dispersed in the pyrocarbon coating. An improvement in the oxidation resistance has been reported when a small amount of SiC (< 5 tool %) is combined with the carbon matrix by CVD [4]. CVD SiC-C containing a trace of carbon was shown to be more resistant to abrasion than CVD SiC. The aim of this study was to prepare carbon fibre-reinforced C-SiC nanomatrix composites, but not nanocomposites, by the CVI technique through the codeposition process. This letter describes the microstructures and properties of the C/C-SiC nanomatrix composite prepared by codeposition. The experimental set-up is illustrated in Fig. 1. CH3SiC13 liquid and C2H2 gas were used as the source, and H2 and N2 gases were used as the carrier and dilutant gases, respectively. The deposition temperature was selected as l l00°C, the total pressure 1000 Pa and CH3SiC13 was carried into the furnace by bubbling H2 carrier gas. The CH3SiC13 vapour flow rate was controlled by the H2 carrier gas flow rate. The gas flow rates were N2 0.1 m 3 h -1 , H 2 0.0018-0.0024 m 3 h -1 and C2H2 0.02 m 3 h -1. The carbon fibre preform was polyacrylonitrile-based carbon felt of density about 0.1 g cm -3. After