PP was used as basic resin, the polyolefin elastomer (POE, ethylene -octene of polymer) and TPV were used as the impact modifier for PP as basic resin in this paper. The processability , crystallizing behavior and mechanical properties of PP/POE and PP/EPDM blends were analyzed comparitively by Torque Rheometer, melt flowing rate and Differential Scanning Calorimetry (DSC) and their mechanical properties were tested . The results showed that POE was superior to EPDM on processability and toughening effect.