A propylene resin composition comprising: a propylene-based polymer; an ethylene-α-olefin copolymer, the ethylene-α-olefin copolymer not containing a monomer unit derived from propylene; and a filler, wherein parameters W, X and Y to be defined below satisfy the following expression: 1.46 ≤ Y / X / W × 100 wherein W represents a total content (% by mass) of a xylene-insoluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, X represents a total content (% by mass) of a xylene-soluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, and Y represents an amount (% by mass) of a long-duration relaxation component measured by pulse NMR, in a molded article obtained by injection molding a propylene resin composition into a mold cavity of 100 mm (width) × 400 mm (length) × 3 mm (thickness) under conditions of a cylinder temperature of 220°C, a mold temperature of 50°C and an injection speed of 23 mm/sec wherein a content of the propylene-based polymer is 20 to 70% by mass, a content of the ethylene-α-olefin copolymer is 10 to 40% by mass, and a content of the filler is 10 to 40% by mass. a propylene-based polymer; an ethylene-α-olefin copolymer, the ethylene-α-olefin copolymer not containing a monomer unit derived from propylene; and a filler, wherein parameters W, X and Y to be defined below satisfy the following expression: 1.46 ≤ Y / X / W × 100 wherein W represents a total content (% by mass) of a xylene-insoluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, X represents a total content (% by mass) of a xylene-soluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, and Y represents an amount (% by mass) of a long-duration relaxation component measured by pulse NMR, in a molded article obtained by injection molding a propylene resin composition into a mold cavity of 100 mm (width) × 400 mm (length) × 3 mm (thickness) under conditions of a cylinder temperature of 220°C, a mold temperature of 50°C and an injection speed of 23 mm/sec wherein a content of the propylene-based polymer is 20 to 70% by mass, a content of the ethylene-α-olefin copolymer is 10 to 40% by mass, and a content of the filler is 10 to 40% by mass. wherein W represents a total content (% by mass) of a xylene-insoluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, X represents a total content (% by mass) of a xylene-soluble component in the propylene-based polymer and the ethylene-α-olefin copolymer, based on the total mass of the propylene-based polymer and the ethylene-α-olefin copolymer, and Y represents an amount (% by mass) of a long-duration relaxation component measured by pulse NMR, in a molded article obtained by injection molding a propylene resin composition into a mold cavity of 100 mm (width) × 400 mm (length) × 3 mm (thickness) under conditions of a cylinder temperature of 220°C, a mold temperature of 50°C and an injection speed of 23 mm/sec wherein a content of the propylene-based polymer is 20 to 70% by mass, a content of the ethylene-α-olefin copolymer is 10 to 40% by mass, and a content of the filler is 10 to 40% by mass.