Latent heat storage systems can improve the energy use efficiency and conserve limited energy resources. Microcapsules of lauric acid ( LA) as the core and melamineformaldehyde (MF) resin as the shell were prepared as phase change material for latent heat thermal storage by in situ polymerization. The obtained microcapsules were characterized in their surface morphology, particle sizes, thermal properties, thermal cycling, and heat insulation test. Scanning electron microscope analysis suggests that the obtained microcapsules have a spherical shape and smooth surface, and the shell material presents a round shell layer associated with an inner porous structure. Differential scanning calorimeter measurement indicates that the fusion enthalpy of encapsulated LA is 84.96 J/g, which corresponds to 46.2% by weight of core content. The accelerated thermal cycling test proves that the melting temperature of encapsulated LA has little change after 70 thermal cycles. The heat insulation test indicates that LA microcapsules mixed with acrylic latex coating as a kind of smart coating can reduce the indoor temperature fluctuations. The preceding results showed that the MF/LA microcapsules possess good potential as a latent heat storage material. DOI: 10.1061/(ASCE)EY.1943-7897.0000053. (C) 2011 American Society of Civil Engineers.