Abstract: The present invention is directed to a method for preparing cylindrical members for paper containers having a thermoplastic resin layer as the innermost layer by cylindrically forming a preform sheet made up of a laminate comprising at least a paper layer and the thermoplastic resin layer, the laminate is arranged so that the thermoplastic layer becomes the innermost layer of the paper containers and is selected from the group consisting of polyesters and ethylene/vinyl alcohol copolymers. The method includes the steps of folding the innermost layer along one edge of the preform sheet back over itself, irradiating the folded edge and another edge of the preform sheet both of which are made of the thermoplastic resin layer of polyesters or ethylene/vinyl alcohol copolymers using a carbon dioxide gas laser irradiation, thereby softening or melting the thermoplastic resin layer, overlapping the irradiated edges, and pressing the overlapped portion to seal the thermoplastic resin layers together.