A novel poly (ethylene glycol)/ZSM-5 composite was fabricated by a simple way, and it was characterized and evaluated for heat energy storage. The composite PCMs was fabricated through introducing PEG to mesoporous pores of ZSM-5 assisted with a vacuum impregnation system. XRD and FTIR analysis results showed that there was no chemical reaction happened between PEG4000 and ZSM-5. DSC and TGA analysis results indicated that the as-prepared PCMs has outstanding latent heats and superb thermal stability. The latent heat of the as-prepared PCMs achieves to 76.37 J/g without any leakiness. Compare with pure PEG, the thermal conductivity of as-prepared PCMs was improved 200%, which means selecting ZSM-5 serve as the supporting material was an effective way to enhance the thermal conductivity. Exudation stability tests results showed that the doping of PEG can reach up 50 wt% without any leakage when the composite undergoing the melting process. According to the above analysis, the prepared composite with good thermal stability, high latent heats and excellent thermal conductivity is very suitable for heat energy storage. (C) 2018 Elsevier Ltd. All rights reserved.