A polypropylene-based resin composition comprising: 5 to 99 % by weight of a polypropylene resin having a structure with long chain branches, and 1 to 95 % by weight of a propylene-based block copolymer produced by sequential polymerization, which comprises: (Y-1) a propylene (co)polymer, and (Y-2) a propylene-ethylene copolymer, said resin having the following properties (X-i) to (X-iv): (X-i): MFR of 0.1 to 30.0 g/10 minutes (X-ii): molecular weight distribution Mw/Mn of 3.0 to 10.0 measured by GPC and Mz/Mw of 2.5 to 10.0 (X-iii): melt tension (unit: g) satisfying the relationship: log MT ≥ - 0.9 × log MFR + 0.7, or MT ≥ 15 (X-iv): content of p-xylene soluble components at 25 °C of less than 5 % by weight based on the total amount of said resin, and said block copolymer having the following properties (Y-i) to (Y-vi): (Y-i): ratios of the amounts of said (Y-1) and (Y-2) of 50 to 99 % by weight and 1 to 50 % by weight, respectively, with the proviso that each ratio is calculated based on the total weight of said block copolymer regarded as 100 % by weight (Y-ii): MFR of said block copolymer of 0.1 to 200.0 g/10 minutes (Y-iii): melting point of said block copolymer of more than 155 °C (Y-iv): the ethylene content of said (Y-2) of more than 38.0 and less than 60.0 % by weight, with the proviso that the ethylene content is calculated based on the total weight of monomers constructing said (Y-2) regarded as 100 % by weight (Y-v): the intrinsic viscosity [η] (unit: dl/g) of said (Y-2) measured at 135 °C in decalin of 7.3 or more (Y-vi): the comonomer content of said (Y-1) of 10 % by weight or less. 5 to 99 % by weight of a polypropylene resin having a structure with long chain branches, and 1 to 95 % by weight of a propylene-based block copolymer produced by sequential polymerization, which comprises: (Y-1) a propylene (co)polymer, and (Y-2) a propylene-ethylene copolymer, said resin having the following properties (X-i) to (X-iv): (X-i): MFR of 0.1 to 30.0 g/10 minutes (X-ii): molecular weight distribution Mw/Mn of 3.0 to 10.0 measured by GPC and Mz/Mw of 2.5 to 10.0 (X-iii): melt tension (unit: g) satisfying the relationship: log MT ≥ - 0.9 × log MFR + 0.7, or MT ≥ 15 (X-iv): content of p-xylene soluble components at 25 °C of less than 5 % by weight based on the total amount of said resin, and said block copolymer having the following properties (Y-i) to (Y-vi): (Y-i): ratios of the amounts of said (Y-1) and (Y-2) of 50 to 99 % by weight and 1 to 50 % by weight, respectively, with the proviso that each ratio is calculated based on the total weight of said block copolymer regarded as 100 % by weight (Y-ii): MFR of said block copolymer of 0.1 to 200.0 g/10 minutes (Y-iii): melting point of said block copolymer of more than 155 °C (Y-iv): the ethylene content of said (Y-2) of more than 38.0 and less than 60.0 % by weight, with the proviso that the ethylene content is calculated based on the total weight of monomers constructing said (Y-2) regarded as 100 % by weight (Y-v): the intrinsic viscosity [η] (unit: dl/g) of said (Y-2) measured at 135 °C in decalin of 7.3 or more (Y-vi): the comonomer content of said (Y-1) of 10 % by weight or less. (Y-1) a propylene (co)polymer, and (Y-2) a propylene-ethylene copolymer, (X-i): MFR of 0.1 to 30.0 g/10 minutes (X-ii): molecular weight distribution Mw/Mn of 3.0 to 10.0 measured by GPC and Mz/Mw of 2.5 to 10.0 (X-iii): melt tension (unit: g) satisfying the relationship: log MT ≥ - 0.9 × log MFR + 0.7, or MT ≥ 15 (X-iv): content of p-xylene soluble components at 25 °C of less than 5 % by weight based on the total amount of said resin, and (Y-i): ratios of the amounts of said (Y-1) and (Y-2) of 50 to 99 % by weight and 1 to 50 % by weight, respectively, with the proviso that each ratio is calculated based on the total weight of said block copolymer regarded as 100 % by weight (Y-ii): MFR of said block copolymer of 0.1 to 200.0 g/10 minutes (Y-iii): melting point of said block copolymer of more than 155 °C (Y-iv): the ethylene content of said (Y-2) of more than 38.0 and less than 60.0 % by weight, with the proviso that the ethylene content is calculated based on the total weight of monomers constructing said (Y-2) regarded as 100 % by weight (Y-v): the intrinsic viscosity [η] (unit: dl/g) of said (Y-2) measured at 135 °C in decalin of 7.3 or more (Y-vi): the comonomer content of said (Y-1) of 10 % by weight or less.