The effect of solid fillers [(Al,cyclotetramethylene tetranitramine (HMX),ammonium perchlorate (AP)] on the crystallization behavior of PEG was studied by using DSC and WAXD techniques．AI and HMX have no effect on the crystallinity and crystal structure of PEG in composites There is a strong interaction between AP and PEG,which decreases the erystallinity of PEG in the mixtures．Some other metal salts have shown the same strong influence on the crystallization of PEG like AP It was found that they all are soluble in PEG melt．The decrease of crystallinity of PEG in the presence of AP and other metal salts is attributed to the formation of complex between the metal cations and the oxygen atoms of PEG molecules,which prevents the crystallization of PEG molecules in the composites．