A theoretical model describing the thermal conductivity of oxidized meso-porous silicon (meso-PS) was brought forward, which was based on the effective medium theory for the mechanisms of heat transfer in oxidized meso-PS. The factors affecting effective thermal conductivity (ETC) of oxidized meso-PS were analyzed theoretically, and a calculating formula of TC of oxidized meso-PS was given. Meso-PS samples were prepared by double-tank electrochemical corrosion method. Using Micro-Raman spectroscopic technique, the dependence of TC values of oxidized meso-PS samples on porosities of as-prepared meso-PS was studied and the thermal property of oxidized meso-PS with different oxidized temperatures was compared. TC values yielded by Micro-Raman spectroscopic technique of as-prepared meso-PS with porosities of 60%,73.4% and 78.8% oxidized at 300℃ were 8.625，3.846 and 1.817W/(m·K), respectively, while that of as prepared meso-PS with a porosity of 73.4% oxidized at 450℃ and 600℃ were 2.466 and 2.100 W/(m·K), respectively. And their corresponding theoretical ETC values were 4.549,2.432,1.792,2.105 and 2.096 W/(m·K), respectively. It was shown that the theoretical values were in good agreement with experimental data. Oxidized meso-PS with lower TC and desirable mechanical stability is well suited for thermal insulation material, which is attractive to the application in thermal-effect-micro-systems (TEMS).