The microencapsulated polyethylene glycol (PEG) with different molecular weight by a fluidized coating method has been prepared and the crystallization behaviors of polyethylene glycol (PEG) particles in three-dimensional confined volume were investigated by using differential scanning calorimetry (DSC) measurement. The results showed that the width of the crystallization peak of PEG increases and its height gradually diminishes in case that the PEG particles are microencapsulated. Compared with the non-microencapsulated PEG particles, the proportion of the first crystallization peak of microencapsulated PEG particle increases, and that of the second one decreases. The reason for the difference maybe is that the crystallization process of microencapsulated PEG particles are uniform and the crystallization ends when the spherulites touch the wall, thus the opportunity of producing the second crystallization peak was relatively reduced.