The present invention provides a laminated sealant film that has excellent low temperature bag-making properties and heat sealing strength and that comprises a propylene resin and a polyethylene resin, said laminated sealant film satisfying all of conditions 1) to 8) below. 1) The laminated sealant film includes at least a laminate layer and a sealing layer. 2) The laminate layer comprises a resin composition having, as the main component, a polypropylene resin. 3) The sealing layer comprises a resin composition having, as the main component, a mixture of a polypropylene resin and a polyethylene resin. 4) With respect to 100 mass% of the mixture of the polypropylene resin and the polyethylene resin constituting the sealing layer, the polypropylene resin is contained in an amount of 1-90 mass%, and the polyethylene resin is contained in an amount of 10-99 mass%. 5) The polyethylene resin constituting the sealing layer contains not less than 90 mass% of a straight-chain linear polyethylene resin. 6) There is a difference of not less than 15°C between the respective melting points of the straight-chain linear polyethylene resin and the polypropylene resin of the sealing layer. 7) The ratio of the melt flow rate of the polypropylene resin with respect to the melt flow rate of the straight-chain linear polyethylene resin of the sealing layer is 0.5-2.0. 8) The melt flow rates of the straight-chain linear polyethylene resin and the polypropylene resin of the sealing layer are not more than 9 g / 10 minutes.