Provided is a novel cylindrical member having excellent mechanical properties. And to provide a composition containing the cylindrical member, a molded body formed by molding the composition, a structural material formed by the cylindrical member, and a method for manufacturing the cylindrical member. A cylindrical member according to one aspect of the present disclosure includes a plurality of layers, the cylindrical member comprising a first layer and a second layer disposed outside the first layer, An inner surface of the second layer is in direct contact with an outer surface of the first layer, and both the first and second layers contain at least one of a chitin-based compound and a cellulose-based compound. Figure 1

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