Propylene-ethylene (PPE) copolymer was added to high melt-strength polypropylene (HMS PP) for extrusion foaming. PPE postpones polypropylene (PP) crystalization and decreases the optimum foaming temperature. The blend maintains good melt strength and pronounced strain hardening(less than 30%) for a low melt mass flow rate (MFR) of PPE. The small phase separation of PPE (high ethylene content) and PP also favors cell nucleation during foaming. Thus, at lower foaming temperature, the small crystals may function as physical crosslinking, which can help to maintain melt strength and strain hardening behavior around the foaming window. The better cell nucleation and finer cells with higher expansion ratio (ER) in the foam sample were achieved. Combining the advantage of resin elasticity and better foam structure, better toughness was achieved with elongation at break as high as 150%, while maintaining the stiffness.