A Monte Carlo method is devised to determine the extinction coefficients of silicon carbide (SiC) porous media made up of random sphere pores. The optical properties of porous media are obtained from Fresnel's law and Beer's law based on the refractive index of the SiC. The simulation results show that the extinction coefficient of the silicon carbide porous media is strongly dependent on the porosity and pore size. The simulated extinction coefficients agree well with available experimental data in literature. Based on a large number of extinction coefficients from Monte Carlo simulation, we present a correlation of extinction coefficient, by which the radiative thermal conductivity and radiative heat flux in SiC porous media can be calculated conveniently. (C) 2015 Elsevier Ltd. All rights reserved.