Abstract: The phase-change microcapsules based on the palmitic acid (PA) core and silica shell were synthesized by an emulsion templating method through interfacial polycondensation, and the effect of core/shell mass ratio on the morpho-logy, microstructure, thermal energy-storage properties, thermal stability and thermal cycling performance of the resulting microcapsules were investigated extensively. The results indicated that the phase-change microcapsules exhibited a more perfect core-shell structure and a smoother surface with an improvement of the core/shell mass ratio, and the optimum core/shell mass ratio was determined as 60/40, at which the microcapsules achieved the highest thermal energy-storage capability of 98.78 %. The encapsulation of silica shell not only effectively prevents the PA core from leaking and flowing away during the phase-change process but also improves the thermal stability and shape/form stability of the phase-change microcapsules. Moreover, the phase-change microcapsules exhibited good phase-transition reversibility and durability, and therefore they could be applied for thermal energy-storage and thermal management in various industrial and civil areas.