PURPOSE: To obtain a lightweight cylindrical structure with a desired strength by arranging an inner cylindrical film having stretching property and airtightness on the outer surface of an outer cylindrical film made of high strength fibers arranged in the plural directions and also sealing fluid inside the inner cylindrical film.

CONSTITUTION: A cylindrical structure 10 comprises an outer cylindrical film 1 made of high tensile strength fibers such as Aramide fibers arranged in the longitudinal, circumferential and oblique directions respectively and an inner cylindrical film made of rigid rubber or the like having stretching property and airtightness arranged on the inner surface of the outer cylindrical film 1. Further, the inner cylindrical film 2 is provided with a filling port 2a projecting from the outer cylindrical film 1 and a valve 4 is opened/closed for sealing air at a predetermined pressure in the inner cylindrical film 2 through the filling port 2a. The end of the cylindrical structure 10 is inserted into a cylindrical opening part 13 formed on the inner surface of a lightweight coupling 11 made of aluminum or the like and then pressurized so as to bring the outer cylindrical film 1 into pressure contact with the uneven portion of the cylindrical opening part 13, thus engaging the cylindrical structure 10 to the lightweight coupling 11.