Polyxnorphism of α-D-glucose pentalwlmitate has been studied by the comparison of melting points of different crystalline forms obtained under different conditions,by the determination of transition points,and by the observation of cooling and heating curves of the penta-ester.from these investigations,it has been shown at least four polymorphic forms exist in the case of a-D-glucose penta.palmitate:Form Ⅰ,Ⅱ,Ⅲ,and Ⅳ,melting at 61.2°,66.4°,70.7°,and 76.4℃ respectively.Among these four forms,Ⅰ and Ⅲ are stable crystalline form which can be obtained directly by recrystallization under different conditions.Form Ⅱ and Ⅳ have not been obtained by recrysta,llization in this investigation and their existence is inferred from the determination of transition points and from the observation of cooling and heating curves.