Form-stable lauric acid (LA)/silicon dioxide (SiO2) composite phase change materials were prepared using sol-gel methods. The LA was used as the phase change material for thermal energy storage, with the SiO2 acting as the supporting material. The structural analysis of these form-stable LA/SiO2 composite phase change materials was carried out using Fourier transformation infrared spectroscope (FT-IR). The microstructure of the form-stable composite phase change materials was observed by a scanning electronic microscope (SEM). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the LA was well dispersed in the porous network of SiO2. The DSC results indicated that the melting latent heat of the form-stable composite phase change material is 117.21 kJ kg(-1) when the mass percentage of the LA in the SiO2 is 64.8%. The results of the TGA showed that these materials have good thermal stability. The form-stable composite phase change materials can be used for thermal energy storage in waste heat recovery and solar heating systems. (C) 2010 Elsevier B.V. All rights reserved.