This paper deals with the preparation of silica microcapsules containing phase change paraffin wax for thermal energy storage and the determination of their thermal properties. The spherical microcapsule samples respectively containing two types of paraffin wax (with peak melting temperature of 29.3 °C (type P1) and 35.5 °C (type P2), and the fusion heat of 140 J/g (type P1) and 153 J/g (type P2)) as core and chemically and thermally stable silica as shell, were prepared from O/W emulsion systems in the presence of polyvinyl alcohol as stabilizer, and sorbitan monooleate and poilyoxyethylene(20) sorbitan monooleate as emulsifiers. The silica shell formed via hydrolysis and condensation from tetraethyl silicate with acetate acid as catalyst. The fusion heat of the two samples is 101 J/g and 112 J/g respectively. Property of adaptable temperature of the as-made microcapsules is measured through a self-made cell model. The maximum difference between the temperature of the cell with PCM wallpaper and that of the cell with controlled wallpaper is about 1.1 °C.