With the kaolin as raw material, the mesoporous material with high surface area, large pore volume and even pore size distribution, was prepared by microwave radiation method. Then with the mesoporous material as carrier, paraffin as phase change material, the paraffin/mesoporous composite phase change material was synthesized successfully via vacuum absorption. The mesoporous material obtained was characterized and observed by N2 physical adsorption and scanning electron microscopy (SEM)and transmission electron microscopy (TEM), which clearly revealed the structures of the samples. FTIR results confirmed that the paraffin was incorporate into the framework of the synthesized materials. The thermal performance of the composite material was characterized by differential scanning calorimeter (DSC).The diffused-exudative circle method was used to determine the stability of composite phase change material. The result showed that: the surface area of mesoporous material was 961.64m2/g, the pore volume was 0.854mL/g, and the average pore size was 2.78nm; the best adsorption quantity of 50% for mesoporous material; the phase change temperature was 60.5℃，phase change latent heat was 115.85J/g; the paraffin was considered as being imbedded into the net of the mesoporous material, and the composite material was provided with good thermal reliability and good chemical compatibility. Key Words: phase change material；paraffin; mesoporous material; kaolin; microwave radiation method