Taking paraffin as phase change material, MCM-41 mesoporous silica materials as carrier, the paraffin/MCM-41 composite phase change thermal energy storage materials were synthesized successfully via solution immersion. The morphology was observed by scan electron microscopy (SEM), transmission electron microscopy (TEM) images and clearly revealed the structure of molecular sieves and paraffin/MCM-41. The synthesized materials were characterized by thermal gravimetry/differential scanning calorimeter (TG-DSC). The results verified the good thermal stability of the synthesized material. FT-IR results confirmed that the paraffin was incorporated into the framework of mesoporous materials. The results showed that the paraffin’s maximum of PCM was 40%wt, phase change temperature was 66.6℃, phase change latent heat was 135.3J/g; there is no reaction between the paraffin and the silicon dioxide, paraffin was imbedded into the net of silicon dioxide The form-stable paraffin/MCM-41 composite PCM was considered as an effective latent heat thermal energy storage material due to good thermal reliability and good chemical compatibility.