A numerical model was developed in order to describe the thermal-gradient chemical vapor infiltration (CVI) for the production of SiCW/Al2O3 composite. The proposed model considered reaction, diffusion and deposition of alumina within the porous preform. The cubic array of disconnected cylinders model was proposed in order to represent the porous structure of the preform and the composite. The experimental results of CVI were in good agreement with the calculated results. The effects of total pressure, healing temperature and initial surface temperature on the final residual porosity ansi the infiltration time were investigated. The heating temperature and the initial surface temperature had a larger effect on the porosity: and the infiltration time than did the total pressure. In order to produce a dense composite, the initial surface temperature must decrease with increasing heating temperature.