The melt fracture and morphology of HOPE blends (HDPE/EPDM and HDPE/zinc-neutralized sulfonated EPDM, Zn-SEPDM, plasticized with different plasticizers) were studied through a capillary rheometer and scanning electron microscopy (SEM). The results show that the addition of a small amount of GR (modified glyptal resin) to Zn-SEPDM reduces the melt elasticity and the tendency of extrudate distortion of HDPE/Zn-SEPDM/GR blend considerably as compared to HDPE/EPDM and HDPE/Zn-SEPDM/Zn-St blends, resulting in improvement of processability of the blend.