There is provided a package bag provided with a liquid pouring nozzle wherein permanent deformation of a pouring path for a packing material of the liquid pouring nozzle in a swollen direction is prevented surely to completely prevent accidental invasion of air into a package bag main body in the pouring of the packing material but also the self-sealing one-way function can be sufficiently developed in the pouring stop of the packing material. The package bag according to the invention is characterized in that the liquid pouring nozzle is constructed by laying front and rear laminate films, each of which films comprising a base film layer and a high-melting sealant layer and a low-melting sealant layer sandwiching the base film layer therebetween so as to face the high-melting sealant layers to each other and fusion-joining them at their peripheral portions other than base end sides to each other, and the base end portion of the liquid pouring nozzle is fusion-joined to a sealant layer on an inner surface of a soft package bag main body through low-melting sealant layers on the outer surface of the nozzle at a posture of protruding the nozzle from a side portion of the soft package bag main body, and also in that the opposed high-melting sealant layers in the base end portion of the liquid pouring nozzle are temporarily fused to each other.