Abstract: This paper describes the cooling crystallization exothermic diagrams of melt spcimen by using differential scanning calorimetry(DSC) microscope to analyze its morphological structure.It was found in the experiment that the glass fiber(GF) has the function of heterogeneous nucleation for polypropylenc(PP) and improves the crystalline morphology of PP.High density polyethy lcnc(HDPE) has synergetic effect for hcterogeneous nucleation,and improves the brittlness of matrix resin of PP.