The isothermal and nonisothermal crystallizations of glycidyl methacrylate／styrene (GMA／St) multimonomer melt-grafted polypropylene [PP-g-(GMA-co-St)] were investigated by DSC

crystals of the grafted PP were observed through polarized optical microscope．Avrami equation was used to analyze the kinetics of crystallization．The crystallization of the grafted PP was heterogeneous nucleated

and three dimensional growth of spherulites can be observed as in the case of neat PP．Compared to neat PP

the crystallization temperature(Tc) of the grafted PP increased 16～19℃ and the overall crystallization rate was accelerated dramatically．The grafts of GMA-co-St reduced the interfacial free energy of the surfaces of the crystal nuclei and promoted the heterogeneous nucleating．When the degree of grafting was not very high

Tc and overall crystallization rate of the grafted PP increased with increasing the degree of grafting．In the range of higher degree of grafting

with increasing the degree of grafting

Tc stopped rising and the overall crystallization rate was slowed down due to the severe obstruction of the grafts to the growth of the crystal．