Polypropylene(PP) and nylon 6 were extruded on a single screw extruder. Nylon 6 could disperse in an ellipsoidal form in the PP matrix. When the blends were compression-molded at a temperature between the melting temperature of PP and that of nylon 6, these ellipsoids were ma ntained in the matrix. While the elastic recovery was improved by the existence of nylon 6 ellipsoids, the tensile strength of the blend decreased. Differential scanning calorimetry(DSC) analysis showed that nylon 6 ellipsoids could affect the crystallization behavior of PP slightly. To see if the above results could also be obtained in PP/nylon 6 blend filaments, the mechanical properties, the morphology, and the melting and crystallization of the blend filaments were investigated in this study.