Disclosed is a propylene-diene copolymer resin having excellent melt tension, with improved melt strength, high molecular weight and broad molecular weight distribution by using a specific metallocene catalyst system. The present invention provides a propylene-diene copolymer resin produced by polymerizing propylene and a diene compound of C4-C20 by using a metallocene catalyst system, wherein the propylene-diene copolymer resin has the melt index (2.16 kg load at 230° C.) of 0.1-100 g/10 min and the melt tension (advanced rheometric expansion system (ARES)) of 5-100 g.