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 the content of MPCM. The thermal conductivity of the energy storage mortar with solid MPCM is greater than that of the energy storage mortar with liquid MPCM. The peak temperature of the inner surface of the energy storage mortar with 20% MPCM is 3.1 ℃ lower than that of the cement mortar， the time to reach the peak temperature is 20.5 min later than that of the cement mortar， and the compressive strength of which at the age of 28 d is 9.3 MPa. The energy storage mortar can be used in the building envelope due to its sufficient compressive strength and good ability of energy storage and temperature regulation.