Unvulcanized and dynamically vulcanized blends of isotactic polypropylene (PP) and butadiene-styrene block copolymer (SBS), in the composition range of 10-40 wt % SBS content are prepared in an internal mixer and the vulcanization process is investigated through time-torque curves. Study of melt rheological properties of these blends are reported, and results show the effects of blend composition and shear rate on melt viscosity and melt elasticity. Blending of PP with SBS increases melt viscosity and decreases extrudate distortion. Dynamically vulcanized blends show higher melt viscosity and lower melt elasticity than corresponding unvulcanized blends with no melt fracture in the studied range.