The energy storage mortar for buildings was developed by incorporating microencapsulated phase change material (MPCM) into cement mortar. The microscopic morphology, phase change characteristics, thermal stability, thermal conductivity, thermal and mechanical properties of energy storage mortar were investigated. The results show that the thermal conductivity of energy storage mortar decreases with the increase of MPCM. The thermal conductivity of the energy storage mortar when the PCM was solid was greater than that of the energy storage mortar when the PCM was liquid. The surface peak temperature of the energy storage mortar with 20% MPCM is 3.1 ℃ lower than that of the cement mortar, the time reaching the peak temperature delays 20.5 min than that of the cement mortar. Its compressive strength at the age of 28 days is 9.3 MPa. It can be used to store energy for the building envelope because it has sufficient compressive strength and good energy storage temperature regulation effect.